Fix log stream bug

[StrawnSC]

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Fixes microsoft/azure-container-apps#299
Since log streaming (and ssh) require an active replica (but ACA allows replicas to scale down to zero), we try to ping the container app's FQDN for these commands. If there are networking restrictions, the command fails at that point. This prevents users from log streaming or using ssh. With this fix, we ignore failures when pinging the app (warning the user to ensure there is an alive replica) and allows the ssh/logstream command to resume

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