增加demo脚本的错误退出机制，避免脏数据产生

**Describe the bug**
执行demo安装， make demo ，出现如下错误：
```sh
bash demo/install-demo.sh default
++ dirname demo/../test/e2e/scripts/istio.sh
+ BASEDIR=demo/../test/e2e/scripts/../../..
+ COMMON_DIR=demo/../test/e2e/scripts/../../../test/e2e/common
+ '[' -z '' ']'
+ export ISTIO_NAMESPACE=istio-system
+ ISTIO_NAMESPACE=istio-system
+ '[' -z '' ']'
+ export ISTIO_VERSION=1.14.5
+ ISTIO_VERSION=1.14.5
+ kubectl create ns istio-system
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ true
+ rm -rf /root/.aeraki/istio/istio-config.yaml
+ mkdir -p /root/.aeraki/istio
+ envsubst
++ istioctl version --remote=false
++ grep 1.14.5
demo/../test/e2e/scripts/istio.sh: line 37: istioctl: command not found
+ '[' -n '' ']'
+ curl -L https://istio.io/downloadIstio
+ ISTIO_VERSION=1.14.5
+ sh -
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 101 100 101 0 0 109 0 --:--:-- --:--:-- --:--:-- 109
100 4856 100 4856 0 0 3896 0 0:00:01 0:00:01 --:--:-- 4742k

Downloading istio-1.14.5 from https://github.com/istio/istio/releases/download/1.14.5/istio-1.14.5-linux-amd64.tar.gz ...

Istio 1.14.5 Download Complete!

Istio has been successfully downloaded into the istio-1.14.5 folder on your system.

Next Steps:
See https://istio.io/latest/docs/setup/install/ to add Istio to your Kubernetes cluster.

To configure the istioctl client tool for your workstation,
add the /root/cloud/aeraki/istio-1.14.5/bin directory to your environment path variable with:
export PATH="$PATH:/root/cloud/aeraki/istio-1.14.5/bin"

Begin the Istio pre-installation check by running:
istioctl x precheck

Need more information? Visit https://istio.io/latest/docs/setup/install/
+ sudo mv /root/cloud/aeraki/istio-1.14.5/bin/istioctl /usr/local/bin/
+ /usr/local/bin/istioctl install -f /root/.aeraki/istio/istio-config.yaml -y
Error: Get "https://cls-88t58h3p.ccs.tencent-cloud.com/api?timeout=32s": http: server gave HTTP response to HTTPS client
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ '[' -z '' ']'
++ git log --format=%H -n 1
+ export AERAKI_TAG=d5d0afc6dc12b49f4e117a80fc6c68f69f367c81
+ AERAKI_TAG=d5d0afc6dc12b49f4e117a80fc6c68f69f367c81
+ '[' -z '' ']'
+ export ISTIO_NAMESPACE=istio-system
+ ISTIO_NAMESPACE=istio-system
+ '[' -z '' ']'
+ export AERAKI_NAMESPACE=istio-system
+ AERAKI_NAMESPACE=istio-system
+ '[' -z '' ']'
+ export AERAKI_ISTIOD_ADDR=istiod.istio-system:15010
+ AERAKI_ISTIOD_ADDR=istiod.istio-system:15010
+ '[' -z '' ']'
+ export AERAKI_IS_MASTER=true
+ AERAKI_IS_MASTER=true
+ '[' -z '' ']'
+ export AERAKI_ENABLE_ENVOY_FILTER_NS_SCOPE=false
+ AERAKI_ENABLE_ENVOY_FILTER_NS_SCOPE=false
+ '[' -z '' ']'
+ export AERAKI_IMG_PULL_POLICY=Always
+ AERAKI_IMG_PULL_POLICY=Always
+ '[' -z '' ']'
+ export AERAKI_IMAGE=ghcr.io/aeraki-mesh/aeraki
+ AERAKI_IMAGE=ghcr.io/aeraki-mesh/aeraki
+ '[' -z '' ']'
+ export AERAKI_XDS_ADDR=aeraki.istio-system
+ AERAKI_XDS_ADDR=aeraki.istio-system
+ '[' -z '' ']'
+ export AERAKI_XDS_PORT=:15010
+ AERAKI_XDS_PORT=:15010
+ kubectl create ns istio-system
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ true
+ kubectl create ns istio-system
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ true
+ rm -rf /root/.aeraki/aeraki.yaml
+ mkdir -p /root/.aeraki
+ envsubst
+ '[' '' == mode=tcm ']'
+ kubectl delete crd applicationprotocols.metaprotocol.aeraki.io
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ true
+ kubectl apply -f demo/../test/e2e/scripts/../../../k8s/crd.yaml
Unable to connect to the server: http: server gave HTTP response to HTTPS client
install default demo
+ kubectl create ns meta-dubbo
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ true
+ LabelIstioInjectLabel meta-dubbo
+ ns=meta-dubbo
+ echo meta-dubbo
meta-dubbo
++ kubectl get po -n
++ grep istiod
++ awk '{print $1}'
++ xargs kubectl get po -o yaml -n
++ grep -A 1 REVIS
++ grep value:
++ awk '{print $2}'
Error: flag needs an argument: 'n' in -n
See 'kubectl get --help' for usage.
Error: flag needs an argument: 'n' in -n
See 'kubectl get --help' for usage.
+ label=
+ echo

+ '[' '' '!=' '' ']'
+ kubectl label namespace meta-dubbo istio-injection=enabled --overwrite=true
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ return 0
+ kubectl apply -f demo/../demo/metaprotocol-dubbo/dubbo-sample.yaml -n meta-dubbo
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl apply -f demo/../demo/metaprotocol-dubbo/serviceentry.yaml -n meta-dubbo
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl apply -f demo/../demo/metaprotocol-dubbo/destinationrule.yaml -n meta-dubbo
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl create ns meta-thrift
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ LabelIstioInjectLabel meta-thrift
+ ns=meta-thrift
+ echo meta-thrift
meta-thrift
++ kubectl get po -n
++ grep istiod
++ awk '{print $1}'
++ xargs kubectl get po -o yaml -n
++ grep -A 1 REVIS
++ grep value:
++ awk '{print $2}'
Error: flag needs an argument: 'n' in -n
See 'kubectl get --help' for usage.
Error: flag needs an argument: 'n' in -n
See 'kubectl get --help' for usage.
+ label=
+ echo

+ '[' '' '!=' '' ']'
+ kubectl label namespace meta-thrift istio-injection=enabled --overwrite=true
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ return 0
+ kubectl apply -f demo/../demo/metaprotocol-thrift/thrift-sample.yaml -n meta-thrift
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl apply -f demo/../demo/metaprotocol-thrift/destinationrule.yaml -n meta-thrift
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl create cm rate-limit-config -n meta-thrift --from-file demo/../demo/metaprotocol-thrift/rate-limit-server/config.yaml
Unable to connect to the server: http: server gave HTTP response to HTTPS client
+ kubectl apply -f demo/../demo/metaprotocol-thrift/rate-limit-server/rate-limit-server.yaml -n meta-thrift
Unable to connect to the server: http: server gave HTTP response to HTTPS client
make: *** [demo] Error 1
```
前面步骤失败后还会继续执行下面的脚本，这完全是没必要的，有可能还会导致重新安装时出现各种非预期行为

建议增加错误退出逻辑 ，以便使用者及时解决问题并重新安装