Make handlers test whether filters are callable and not if they exist

pyrogram/client/handlers/callback_query_handler.py

@@ -49,6 +49,6 @@ class CallbackQueryHandler(Handler):
     def check(self, callback_query):
         return (
             self.filters(callback_query)
-            if self.filters
+            if callable(self.filters)
             else True
         )

pyrogram/client/handlers/deleted_messages_handler.py

@@ -50,6 +50,6 @@ class DeletedMessagesHandler(Handler):
     def check(self, messages):
         return (
             self.filters(messages.messages[0])
-            if self.filters
+            if callable(self.filters)
             else True
         )

pyrogram/client/handlers/message_handler.py

@@ -50,6 +50,6 @@ class MessageHandler(Handler):
     def check(self, message):
         return (
             self.filters(message)
-            if self.filters
+            if callable(self.filters)
             else True
         )