Auth: redact message when already logged in

If FB is giving you a hard time while trying to authenticate, then you might mistakenly login while already being logged in, so move the `redact` command above  "already logged in" check

mautrix_facebook/commands/auth.py

@@ -59,13 +59,14 @@ async def login(evt: CommandEvent) -> None:
     if len(evt.args) < 2:
         await evt.reply("Usage: `$cmdprefix+sp login <email> <password>`")
         return
-    elif evt.sender.client:
-        await evt.reply("You're already logged in")
-        return
 
     email, password = evt.args[0], " ".join(evt.args[1:])
     await evt.az.intent.redact(evt.room_id, evt.event_id)
 
+    if evt.sender.client:
+        await evt.reply("You're already logged in")
+        return
+
     state = AndroidState()
     state.generate(evt.sender.mxid)
     api = AndroidAPI(state, log=evt.sender.log.getChild("login-api"))