fix: index error on method get_dialog_message

Author: thalissonvs

pydoll/browser/page.py

@@ -146,7 +146,7 @@ async def get_dialog_message(self) -> str:
         """
         if not await self.has_dialog():
             raise LookupError('No dialog present on the page')
-        return self._connection_handler.dialog['message']
+        return self._connection_handler.dialog['params']['message']
 
     async def accept_dialog(self):
         """