Remove unicode <200b> characters from $match

Occasionally Zero Width Spaces appear between the '>' and the
indexnumber and the tag appears to be not working without any apparent
reason. This PR removes those Zero Width Spaces.

syntax/tag.php

@@ -42,6 +42,7 @@ function connectTo($mode) {
      */
     function handle($match, $state, $pos, Doku_Handler $handler) {
         $match = substr($match, 14, -2);
+        $match = str_replace("\xE2\x80\x8B", "", $match);
         return array($match);
     }