Merge pull request #150 from Idealien/feature/admin-icon-filter

Adding msls_options_admin_get_flag_icon filter

includes/MslsAdminIcon.php

@@ -228,7 +228,16 @@ public function get_a(): string {
 	 */
 	public function get_icon(): string {
 		if ( 'flag' === $this->iconType ) {
-			return ! is_string( $this->language ) ? '' : sprintf( '<span class="flag-icon %s">%s</span>',
+			/**
+			* Use your own filename for the flag-icon
+			* @since 2.6.1
+			*
+			* @param MslsAdminIcon $icon
+			* @param string $language
+			*/
+			$icon = apply_filters( 'msls_options_admin_get_flag_icon', $this, $this->language );
+
+      return sprintf( '<span class="flag-icon %s">%s</span>',
 				( new IconSvg() )->get( $this->language ),
 				$this->language
 			);