Followup to r1600331, no need to say bye if the connection failed.

* subversion/libsvn_subr/gpg_agent.c
  (find_running_gpg_agent): If connect fails there's no reason to say bye.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1600348 13f79535-47bb-0310-9956-ffa450edef68