search-tab: Don't handle clicks on inactive icon

The icon set as secondary icon of the search entry depends on whether
a search is active or not - clicking the icon should reset the entry
only in the former case. This is implemented by connecting/disconnecting
the 'secondary-icon-clicked' signal when updating the icon, but an
additional signal connection was left-over when refactoring the search
entry, resulting in clicks on the inactive icon removing the hint text.
Fix by removing the stray signal connection.

https://bugzilla.gnome.org/show_bug.cgi?id=646855

js/ui/viewSelector.js

@@ -152,10 +152,6 @@ SearchTab.prototype = {
             return true;
         }));
 
-        this._entry.connect('secondary-icon-clicked', Lang.bind(this,
-            function() {
-                this._reset();
-            }));
         this._entry.connect('notify::mapped', Lang.bind(this, this._onMapped));
 
         global.stage.connect('notify::key-focus', Lang.bind(this, this._updateCursorVisibility));