upgrade python packages to python3

tasks/postgresql.yaml

@@ -2,7 +2,7 @@
 
 - name: debian packages required for database management
   apt:
-    pkg: python-psycopg2
+    pkg: python3-psycopg2
   delegate_to: "{{ (nextcloud_database_host != 'localhost') | ternary(nextcloud_database_host,inventory_hostname) }}"
 
 - name: postgresql user