(js) Unselect message when selecting same mailbox

UI/WebServerResources/js/Mailer/Mailer.app.js

@@ -103,6 +103,7 @@
             controllerAs: 'viewer'
           }
         },
+        onExit: onExitMessage,
         resolve: {
           stateMessage: stateMessage
         }
@@ -268,6 +269,14 @@
     }
   }
 
+  /**
+   * @ngInject
+   */
+  onExitMessage.$inject = ['stateMailbox'];
+  function onExitMessage(stateMailbox) {
+    stateMailbox.selectedMessage = -1;
+  }
+
   /**
    * @ngInject
    */