use svg icon instead of png file

public/app/core/components/navbar/navbar.html

@@ -3,7 +3,7 @@
 			<div class="top-nav-btn top-nav-menu-btn">
 				<a class="pointer" ng-click="ctrl.contextSrv.toggleSideMenu()">
 					<span class="top-nav-logo-background">
-						<img class="logo-icon" src="img/fav32.png"></img>
+						<img class="logo-icon" src="img/grafana_icon.svg"></img>
 					</span>
 					<i class="fa fa-caret-down"></i>
 				</a>