update_rss_feed: juxtapose pdo and ORM commit on timestamp update

If for whatever reason $pdo holds a DDL lock on ttrss_entries, it could
block ORM's save, leading to a deadlock. To work around this, call
$pdo->commit() before ORM::for_table()->save().

classes/rssutils.php

@@ -786,13 +786,13 @@ class RSSUtils {
 					// dupes when the entry gets purged and reinserted again e.g.
 					// in the case of SLOW SLOW OMG SLOW updating feeds
 
+					$pdo->commit();
+
 					$entry_obj = ORM::for_table('ttrss_entries')
 						->find_one($base_entry_id)
 						->set('date_updated', Db::NOW())
 						->save();
 
-					$pdo->commit();
-
 					continue;
 				}