Add allowNonHttpProtocols to typings

typings/xterm.d.ts

@@ -1179,6 +1179,13 @@ declare module 'xterm' {
       * @param range The buffer range of the link.
       */
      leave?(event: MouseEvent, text: string, range: IBufferRange): void;
+    
+     /**
+      * Whether to allow the use of non HTTP URLs in OscLinkProvider. When false, any usage of non
+      * HTTP URLs will be ignored. Enabling this option without proper protection in activate function
+      * may allow XSS.
+      */
+     allowNonHttpProtocols?: boolean;
   }
 
   /**