Fix QR code icon

src/partials/messenger.receiver.html

@@ -7,7 +7,7 @@
 
         <div class="header-buttons">
             <md-button aria-label="chat" class="md-icon-button" ng-show="ctrl.controllerModel.canShowQr()" ng-click="ctrl.showQr()">
-                <md-icon><img src="public/img/ic_qr.svg" alt="QR"></md-icon>
+                <md-icon><img src="img/ic_qr.svg" alt="QR"></md-icon>
             </md-button>
 
             <md-button aria-label="chat" class="md-icon-button" ng-show="ctrl.controllerModel.canEdit()" ng-click="ctrl.edit()">