demo(popover): fix typo in template url

src/popover/docs/demo.js

@@ -1,7 +1,7 @@
 angular.module('ui.bootstrap.demo').controller('PopoverDemoCtrl', function ($scope) {
   $scope.dynamicPopover = {
     content: 'Hello, World!',
-    templateUrl: 'myTemplatePopover.html',
+    templateUrl: 'myPopoverTemplate.html',
     title: 'Title'
   };
 });