Make bail safe for non-string inputs and uninitialized events
Make bail safe for non-string inputs and uninitialized events

It was possible to bail on certain events before the 'client' and/or
'check' properties are initialized. In those cases you get a
stacktrace (over multiple lines) instead of the initial error message.

With this change you always get the error message that the handler sent.

nyxcharon/sensu-plugins-quay,upfluence/sensu-plugin,zbintliff/sensu-plugin,sensu-plugins/sensu-plugin