router test failing with TimeoutExpired from mb command

When running the router test it has been periodically failing with the following error:

```
...
Indexing documents in router-test-results
10-09-2021T18:56:46 Sleeping for 6s before next test
10-09-2021T18:56:52 Generating config for termination passthrough with 200 clients 0 keep alive requests and path /1024.html
10-09-2021T18:56:53 Copying mb config http-scale-passthrough.json to pod http-scale-client-6fc5db9645-9lpld
10-09-2021T18:56:55 Executing sample 1/1 using termination passthrough with 200 clients and 0 keepalive requests
Executing 'mb -i /tmp/http-scale-passthrough.json -d 1 -o /tmp/results.csv'
Traceback (most recent call last):
File "/usr/lib64/python3.6/subprocess.py", line 425, in run
stdout, stderr = process.communicate(input, timeout=timeout)
File "/usr/lib64/python3.6/subprocess.py", line 863, in communicate
stdout, stderr = self._communicate(input, endtime, timeout)
File "/usr/lib64/python3.6/subprocess.py", line 1535, in _communicate
self._check_timeout(endtime, orig_timeout)
File "/usr/lib64/python3.6/subprocess.py", line 891, in _check_timeout
raise TimeoutExpired(self.args, orig_timeout)
subprocess.TimeoutExpired: Command 'mb -i /tmp/http-scale-passthrough.json -d 1 -o /tmp/results.csv' timed out after 5 seconds

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/workload/workload.py", line 92, in
exit(main())
File "/workload/workload.py", line 66, in main
result_codes, p95_latency, p99_latency, avg_latency = run_mb(args.mb_config, args.runtime, args.output)
File "/workload/workload.py", line 35, in run_mb
timeout=int(runtime) * 5)
File "/usr/lib64/python3.6/subprocess.py", line 430, in run
stderr=stderr)
subprocess.TimeoutExpired: Command 'mb -i /tmp/http-scale-passthrough.json -d 1 -o /tmp/results.csv' timed out after 5 seconds
command terminated with exit code 1
```

Example env.sh
```
# General
export KUBECONFIG=/root/gcp/gcp_kube_3
export UUID=$(uuidgen)

# ES configuration
export ES_SERVER=ES_SERVER
export ES_INDEX=${ES_INDEX:-router-test-results}
export ES_SERVER_BASELINE=ES_SERVER_BASELINE

# Gold comparison
COMPARE_WITH_GOLD="false"
ES_GOLD=${ES_GOLD:-${ES_SERVER}}
GOLD_SDN=${GOLD_SDN:-openshiftsdn}
GOLD_OCP_VERSION=4.8

# Environment setup
NUM_NODES=$(oc get node -l node-role.kubernetes.io/worker --no-headers | grep -cw Ready)
ENGINE=${ENGINE:-podman}
KUBE_BURNER_RELEASE_URL=${KUBE_BURNER_RELEASE_URL:-https://github.com/cloud-bulldozer/kube-burner/releases/download/v0.11/kube-burner-0.11-Linux-x86_64.tar.gz}
KUBE_BURNER_IMAGE=quay.io/cloud-bulldozer/kube-burner:latest
TERMINATIONS=${TERMINATIONS:-"http edge passthrough reencrypt mix"}
INFRA_TEMPLATE=http-perf.yml.tmpl
INFRA_CONFIG=http-perf.yml
export SERVICE_TYPE=${SERVICE_TYPE:-NodePort}
export NUMBER_OF_ROUTERS=${NUMBER_OF_ROUTERS:-1}
#export NUMBER_OF_ROUTERS=${NUMBER_OF_ROUTERS:-2}
export HOST_NETWORK=${HOST_NETWORK:-true}
export NODE_SELECTOR=${NODE_SELECTOR:-'{node-role.kubernetes.io/workload: }'}

# Benchmark configuration
#RUNTIME=${RUNTIME:-60}
#TLS_REUSE=${TLS_REUSE:-true}
#URL_PATH=${URL_PATH:-/1024.html}
#SAMPLES=${SAMPLES:-2}
#QUIET_PERIOD=${QUIET_PERIOD:-60s}
#KEEPALIVE_REQUESTS=${KEEPALIVE_REQUESTS:-"0 1 50"}
# Benchmark configuration
RUNTIME=${RUNTIME:-1}
TLS_REUSE=${TLS_REUSE:-true}
URL_PATH=${URL_PATH:-/1024.html}
SAMPLES=${SAMPLES:-1}
QUIET_PERIOD=${QUIET_PERIOD:-6s}
KEEPALIVE_REQUESTS=${KEEPALIVE_REQUESTS:-"0"}

# Comparison and csv generation
THROUGHPUT_TOLERANCE=${THROUGHPUT_TOLERANCE:-5}
LATENCY_TOLERANCE=${LATENCY_TOLERANCE:-5}
PREFIX=${PREFIX:-$(oc get clusterversion version -o jsonpath="{.status.desired.version}")}
LARGE_SCALE_THRESHOLD=${LARGE_SCALE_THRESHOLD:-24}
METADATA_COLLECTION=${METADATA_COLLECTION:-true}
SMALL_SCALE_BASELINE_UUID="29d520a2-039a-4a1e-b139-83fe2e63fda1"
LARGE_SCALE_BASELINE_UUID="9df8255d-2038-42ed-869d-f748f671da07"
GSHEET_KEY_LOCATION=/root/gcp/gsheet
EMAIL_ID_FOR_RESULTS_SHEET="rzaleski@redhat.com"
```