afk: don't crash if an anonymous message mentions user

get_sender() returns None if telegram didn't send the sender.
this leads to the bot crashing whenever an anonymous message mentions
the user, as the afk event handler doesn't account for this case.

let's add a check to handle this case.

Signed-off-by: Mr.Miss <keselekpermen@mrmiss.wtf>

Author: KenHV

userbot/modules/afk.py

@@ -135,11 +135,7 @@ async def mention_afk(mention):
     back_alivee = datetime.now()
     afk_end = back_alivee.replace(microsecond=0)
     afk_since = "a while ago"
-    if (
-        mention.message.mentioned
-        and not (await mention.get_sender()).bot
-        and ISAFK
-    ):
+    if ISAFK and mention.message.mentioned:
         now = datetime.now()
         datime_since_afk = now - afk_time  # pylint:disable=E0602
         time = float(datime_since_afk.seconds)
@@ -167,14 +163,18 @@ async def mention_afk(mention):
             afk_since = f"`{int(minutes)}m{int(seconds)}s` ago"
         else:
             afk_since = f"`{int(seconds)}s` ago"
-        if mention.sender_id not in USERS:
+
+        is_bot = False
+        if (sender := await mention.get_sender()):
+            is_bot = sender.bot
+        if not is_bot and mention.sender_id not in USERS:
             if AFKREASON:
                 await mention.reply(f"I'm AFK since {afk_since}.\
                         \nReason: `{AFKREASON}`")
             else:
                 await mention.reply(str(choice(AFKSTR)))
             USERS.update({mention.sender_id: 1})
-        else:
+        elif not is_bot and sender:
             if USERS[mention.sender_id] % randint(2, 4) == 0:
                 if AFKREASON:
                     await mention.reply(f"I'm still AFK since {afk_since}.\