Look for existing notice by simple in-check

To detect maybe uncommented notices already present, check for them
using just a simple python x in y check over whole wikicode

Related Task: [FS#138](https://fs.golderweb.de/index.php?do=details&task_id=138)

bots/markpages.py

@@ -268,6 +268,10 @@ class MarkPagesBot( CurrentPageBot ):  # sets 'current_page' on each treat()
         """
         Checks if disc notice which shall be added is already present.
         """
+
+        if self.disc_notice in self.current_wikicode:
+            return True
+
         # Iterate over Templates with same name (if any) to search equal
         # Link to decide if they are the same
         for present_notice in self.current_wikicode.ifilter_templates(