Removes a lot of redundant non-modular changes and maybe fixes cleanbots (#6615)

* oof

* Update _ai_controller.dm

* no need for this anymore

code/modules/modular_computers/file_system/programs/ntnrc_client.dm

@@ -180,7 +180,7 @@
 		else
 			last_message = null
 		return TRUE
-	if(channel?.messages && channel?.messages.len)
+	if(channel?.messages?.len)
 		ui_header = last_message == channel.messages[length(channel.messages)] ? "ntnrc_idle.gif" : "ntnrc_new.gif"
 	else
 		ui_header = "ntnrc_idle.gif"