Remove unused l10n string

src/popup.html

@@ -18,7 +18,7 @@
 </div>
 
 <div class="paneHead">
-    <a id="gotoDashboard" class="extensionURL" href="#" data-extension-url="dashboard.html" title="popupTipDashboard">uMatrix <span id="version"> </span><span class="fa">&#xf013;</span></a>
+    <a id="gotoDashboard" class="extensionURL" href="#" data-extension-url="dashboard.html">uMatrix <span id="version"> </span><span class="fa">&#xf013;</span></a>
     <div id="toolbarContainer">
         <div id="toolbarLeft" class="toolbar alignLeft">
             <button id="scopeCell" class="dropdown-menu-button" tabindex="-1"></button>