More attempts to restart overseer in container

Increase number of attempted restarts for LVAlert Overseer in
a container from 3 to 100. With only three attempts, it doesn't
even consistently get going again without going into a FATAL state
when the openfire server is simply restarted.

docker/supervisord-lvalert-overseer.conf

@@ -11,3 +11,4 @@ stdout_logfile_maxbytes=0
 redirect_stderr=true
 priority=2
 autorestart=true
+startretries=100