fix(core): add fs_name_hash index to migration

Signed-off-by: Varun Patil <varunpatil@ucla.edu>

core/Migrations/Version13000Date20170718121200.php

@@ -261,6 +261,7 @@ class Version13000Date20170718121200 extends SimpleMigrationStep {
 			$table->addIndex(['storage', 'size', 'fileid'], 'fs_storage_size');
 			$table->addIndex(['fileid', 'storage', 'size'], 'fs_id_storage_size');
 			$table->addIndex(['parent'], 'fs_parent');
+			$table->addIndex(['name'], 'fs_name_hash');
 			$table->addIndex(['mtime'], 'fs_mtime');
 			$table->addIndex(['size'], 'fs_size');
 			if (!$schema->getDatabasePlatform() instanceof PostgreSQL94Platform) {