style(sidemenu): rename signup method to signout

public/app/core/controllers/sidemenu_ctrl.js

@@ -120,7 +120,7 @@ function (angular, _, $, coreModule, config) {
     };
 
     $scope.init = function() {
-      $scope.showSignup = contextSrv.isSignedIn && !config['authProxyEnabled'];
+      $scope.showSignout = contextSrv.isSignedIn && !config['authProxyEnabled'];
       $scope.updateMenu();
       $scope.$on('$routeChangeSuccess', $scope.updateMenu);
     };

public/app/partials/sidemenu.html

@@ -60,7 +60,7 @@
 				<span class="sidemenu-item-text">Grafana admin</span>
 	   	</a>
 		</li>
-		<li ng-if="showSignup">
+		<li ng-if="showSignout">
 			<a href="logout" class="sidemenu-item" target="_self">
 				<span class="icon-circle sidemenu-icon"><i class="fa fa-fw fa-sign-out"></i></span>
 				<span class="sidemenu-item-text">Sign out</span>
@@ -82,7 +82,7 @@
 				<span class="sidemenu-item-text">Exit admin</span>
 	   	</a>
 		</li>
-		<li ng-if="showSignup">
+		<li ng-if="showSignout">
 			<a href="logout" class="sidemenu-item" target="_self">
 				<span class="icon-circle sidemenu-icon"><i class="fa fa-fw fa-sign-out"></i></span>
 				<span class="sidemenu-item-text">Sign out</span>