add mod_conference to modules.conf.in

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@1800 d0543943-73ff-0310-b7d9-9358b9ac24b2

modules.conf.in

 loggers/mod_console
 loggers/mod_syslog
 applications/mod_commands
+applications/mod_conference
 applications/mod_bridgecall
 applications/mod_echo
 applications/mod_ivrtest