make "PUBLIC:" prefix for public messages case-sensitive

modules/ffpb.py

@@ -55,7 +55,7 @@ class MsgHandler(SocketServer.BaseRequestHandler):
 
         target = bot.config.core.owner
         if bot.config.has_section('ffpb'):
-            is_public = data.lstrip().lower().startswith("public:")
+            is_public = data.lstrip().startswith("PUBLIC:")
 
             if is_public and not bot.config.ffpb.msg_target_public is None:
                 data = data[7:].lstrip()