Add newline to final line of groupchatlistener.cpp.

The Linux compiler isn't happy when source files don't end with newline.

indra/newview/groupchatlistener.cpp

@@ -56,4 +56,4 @@ GroupChatListener::GroupChatListener():
 /*
 	static void sendMessage(const std::string& utf8_text, const LLUUID& im_session_id,
 								const LLUUID& other_participant_id, EInstantMessage dialog);
-*/
+*/
\ No newline at end of file