fix: handle Channel.DoesNotExist in remove_self viewset

Signed-off-by: ashnaaseth2325-oss <ashnaaseth2325@gmail.com>

Author: ashnaaseth2325-oss

contentcuration/contentcuration/viewsets/user.py

@@ -333,8 +333,9 @@ def remove_self(self, request, pk=None):
         if not channel_id:
             return HttpResponseBadRequest("Channel ID is required.")
 
-        channel = Channel.objects.get(id=channel_id)
-        if not channel:
+        try:
+            channel = Channel.objects.get(id=channel_id)
+        except Channel.DoesNotExist:
             return HttpResponseNotFound("Channel not found {}".format(channel_id))
 
         if request.user != user and not request.user.can_edit(channel_id):