Bug 1323525 - Clicking "Change Search Settings" in searchbar doesn't work. r=florian

MozReview-Commit-ID: 8lBdSHGd5zk

--HG--
extra : rebase_source : 1f5ef1d1a603ed4acfff3d1f1bb164da1ce1caf0

browser/components/search/content/search.xml

@@ -2124,7 +2124,7 @@
 
       <handler event="mousedown"><![CDATA[
         let target = event.originalTarget;
-        if (!target.classList.contains("searchbar-engine-one-off-item")) {
+        if (target.getAttribute("anonid") == "addengine-menu-button") {
           return;
         }
         // Required to receive click events from the buttons on Linux.