PHP 8.1: wp-login: prevent unnecessary function call

... which could be passing `null` onto a context which doesn't allow for `null`.

Author: jrfnl

src/wp-login.php

@@ -1267,7 +1267,10 @@ function wp_login_viewport_meta() {
 				$errors->add( 'enter_recovery_mode', __( 'Recovery Mode Initialized. Please log in to continue.' ), 'message' );
 			} elseif ( isset( $_GET['redirect_to'] ) && false !== strpos( $_GET['redirect_to'], 'wp-admin/authorize-application.php' ) ) {
 				$query_component = wp_parse_url( $_GET['redirect_to'], PHP_URL_QUERY );
-				parse_str( $query_component, $query );
+				$query           = array();
+				if ( $query_component ) {
+					parse_str( $query_component, $query );
+				}
 
 				if ( ! empty( $query['app_name'] ) ) {
 					/* translators: 1: Website name, 2: Application name. */