Plugin Directory: Search: Restore slug boosting in the search algorithm.

This was a bug introduced in [13640], which went unnoticed due to a desire to reduce reliance upon slugs for search boosting.

Slug boosting has some legitimate uses however, so this is being restored for the time being.

Props jeangalea, gibrown.
See #8225/


git-svn-id: https://meta.svn.wordpress.org/sites/trunk@14809 74240141-8908-4e6f-9713-ba540dce6ec7

Author: dd32

wordpress.org/public_html/wp-content/plugins/plugin-directory/class-plugin-search.php

@@ -278,7 +278,7 @@ public function jetpack_search_es_query_args( $es_query_args, $query ) {
 		$should_match[] = [
 			'multi_match' => [
 				'query'  => $search_phrase,
-				'fields' => $this->localise_es_fields( 'title', 'slug_text' ),
+				'fields' => $this->localise_es_fields( [ 'title', 'slug_text' ] ),
 				'type'   => 'most_fields',
 				'boost'  => 5,
 			],