blueprints.channels: fix close_channel for dms

- dispatcher: add sub() and unsub() alias methods

litecord/blueprints/channels.py

@@ -195,12 +195,16 @@ async def close_channel(channel_id):
         # the request via removing the link between them and
         # the channel on dm_channel_state
         await app.db.execute("""
-        DELETE FROM dm_channel_state (user_id, dm_id)
-        VALUES ($1, $2)
+        DELETE FROM dm_channel_state
+        WHERE user_id = $1 AND dm_id = $2
         """, user_id, channel_id)
 
+        # unsubscribe
+        await app.dispatcher.unsub('channel', channel_id, user_id)
+
         # nothing happens to the other party of the dm channel
-        await app.dispacher.dispatch_user(user_id, 'CHANNEL_DELETE', chan)
+        await app.dispatcher.dispatch_user(user_id, 'CHANNEL_DELETE', chan)
+
         return jsonify(chan)
 
     if ctype == ChannelType.GROUP_DM:

litecord/dispatcher.py

@@ -46,6 +46,12 @@ class EventDispatcher:
                   backend, key, identifier, backend)
         return await self.action(backend, 'unsub', key, identifier)
 
+    async def sub(self, backend, key, identifier):
+        return await self.subscribe(backend, key, identifier)
+
+    async def unsub(self, backend, key, identifier):
+        return await self.unsubscribe(backend, key, identifier)
+
     async def dispatch(self, backend_str: str, key: Any, *args, **kwargs):
         """Dispatch an event to the backend.