Fix: Use the agreed default directory for notus advisories (#704)

The directory should be /var/lib/notus/advisories by default.

(cherry picked from commit f316cad)

Co-authored-by: Björn Ricks <bjoern.ricks@greenbone.net>

Author: mergify[bot]

ospd_openvas/notus.py

@@ -186,7 +186,7 @@ def result_handler(self, res_msg: ResultMessage) -> None:
             timer.start()
 
 
-DEFAULT_NOTUS_FEED_DIR = "/var/lib/openvas/plugins/notus/advisories"
+DEFAULT_NOTUS_FEED_DIR = "/var/lib/notus/advisories"
 
 
 class NotusParser(CliParser):