WPDB: When attempting to fall back to `ext/mysql` in `db_connect()`, return the result of the fall back.

While it doesn't affect Core, we should also be passing the `$allow_bail` parameter, for anything that uses it differently.

Props markoheijnen, johnbillion.

Fixes #33105.


Built from https://develop.svn.wordpress.org/trunk@34478


git-svn-id: http://core.svn.wordpress.org/trunk@34442 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34477';
+$wp_version = '4.4-alpha-34478';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-includes/wp-db.php

@@ -1474,7 +1474,7 @@ class wpdb {
 
 				if ( $attempt_fallback ) {
 					$this->use_mysqli = false;
-					$this->db_connect();
+					return $this->db_connect( $allow_bail );
 				}
 			}
 		} else {