Fix PHP lint

Author: Alex Lende

lib/class-wp-duotone-gutenberg.php

@@ -266,9 +266,9 @@ public static function output_global_styles() {
 
 	/**
 	 * Get the CSS selector for a block type.
-	 * 
+	 *
 	 * @param string $block_name The block name.
-	 * 
+	 *
 	 * @return string The CSS selector or null if there is no support.
 	 */
 	private static function get_selector( $block_name ) {