(PCP-125) Error if fail to configure TLS certs
(PCP-125) Error if fail to configure TLS certs

With this commit we prevent the agent from trying to establish a
WebSocket connection in case the provided TLS certs are not validated by
the boost asio context. This may happen in casse of a cert / key
mismatch or in case of an error when retrieving the password.

puppetlabs/cpp-pcp-client,MikaelSmith/cpp-pcp-client,MikaelSmith/cpp-pcp-client,puppetlabs/cpp-pcp-client,puppetlabs/cpp-pcp-client,puppetlabs/cpp-pcp-client,MikaelSmith/cpp-pcp-client,MikaelSmith/cpp-pcp-client,MikaelSmith/cpp-pcp-client