msg_service : fix log, that wasn't readable

debexpo/controllers/msg_service.py

@@ -14,7 +14,7 @@ class MsgServiceController(BaseController):
             content is the content...
             context, the context that maid the msg appear
         """
-        log.debug("%s : content %s context %s" % (msgStyle, content, context))
+        log.debug("%s : content: %s context: %s" % (msgStyle, content, context))
         c.style = msgStyle
         c.content = content
         c.context = context