Change Max Channel per Category to 49, fix fallback save logic

Author: fourjr

core/thread.py

@@ -1205,16 +1205,16 @@ async def create(
 
         # Schedule thread setup for later
         cat = self.bot.main_category
-        if category is None and len(cat.channels) == 50:
+        if category is None and len(cat.channels) >= 49:
             fallback_id = self.bot.config["fallback_category_id"]
             if fallback_id:
                 fallback = discord.utils.get(cat.guild.categories, id=int(fallback_id))
-                if fallback and len(fallback.channels) != 50:
+                if fallback and len(fallback.channels) < 49:
                     category = fallback
 
             if not category:
                 category = await cat.clone(name="Fallback Modmail")
-                self.bot.config.set("fallback_category_id", category.id)
+                self.bot.config.set("fallback_category_id", str(category.id))
                 await self.bot.config.update()
 
         if (message or not manual_trigger) and self.bot.config["confirm_thread_creation"]: