Errors with containerd runtime

Hello!

```
Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.0", GitCommit:"af46c47ce925f4c4ad5cc8d1fca46c7b77d13b38", GitTreeState:"clean", BuildDate:"2020-12-08T17:59:43Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.0", GitCommit:"af46c47ce925f4c4ad5cc8d1fca46c7b77d13b38", GitTreeState:"clean", BuildDate:"2020-12-08T17:51:19Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}
```

Container runtime - containerd
Kubectl-debug version v0.2.0-rc and v0.1.1

I get this kind of errors in agentless=true and with daemonset agents deployed:
```
kubectl-debug --agentless -n dev oauth-dev-5c885dfd7f-98j2n
Agent Pod info: [Name:debug-agent-pod-46aa6a04-655a-11eb-a63d-00505696f1d5, Namespace:default, Image:aylei/debug-agent:latest, HostPort:10027, ContainerPort:10027]
Waiting for pod debug-agent-pod-46aa6a04-655a-11eb-a63d-00505696f1d5 to run...
Start deleting agent pod oauth-dev-5c885dfd7f-98j2n
error execute remote, unable to upgrade connection: Failed to construct RuntimeManager. Error- failed to dial "/run/containerd/containerd.sock"- context deadline exceeded
error: unable to upgrade connection: Failed to construct RuntimeManager. Error- failed to dial "/run/containerd/containerd.sock"- context deadline exceeded
```
```
kubectl-debug --agentless --port-forward nginx-deployment-668f8b749b-b695l
Agent Pod info: [Name:debug-agent-pod-b8591a5a-655a-11eb-ab03-5254004d77d3, Namespace:default, Image:aylei/debug-agent:latest, HostPort:10027, ContainerPort:10027]
Waiting for pod debug-agent-pod-b8591a5a-655a-11eb-ab03-5254004d77d3 to run...
Forwarding from 127.0.0.1:10027 -> 10027
Forwarding from [::1]:10027 -> 10027
Handling connection for 10027
Start deleting agent pod nginx-deployment-668f8b749b-b695l
error execute remote, Internal error occurred: error attaching to container: failed to mount /tmp/containerd-mount374763324: no such file or directory
error: Internal error occurred: error attaching to container: failed to mount /tmp/containerd-mount374763324: no such file or directory
```

The issue names no source files or tests. Start by reproducing the two kubectl-debug commands with the reported Kubernetes and containerd versions, then trace the agentless and daemonset execution paths; done means both runtime errors are resolved and the commands attach successfully.

Written by the indexing model from the issue text.