vaccum at sync final

added 4 commits

• ddf2c0dc - [DLN/EMF] faster get_ranked_posts_by_created_for_observer_communities by first...
• 45ab5b3a - [DLN] also need to add new index to upgrade script, apparently
• 85da819a - Merge branch 'dn_fast_by_created_for_observer_communitites' into 'develop'
• a78090f4 - vaccuming tables during final step after initial sync

Compare with previous version

changed target branch from master to develop

mentioned in commit 8d5d83d0

merged

mentioned in issue #106 (closed)