prevent dispatch when null

SAS/TMSS/frontend/tmss_webapp/src/authenticate/permission.stack.handler.js

@@ -33,7 +33,9 @@ const PermissionStackUtil = {
              permissionStack.token =  axios.defaults.headers.common['Authorization'];
              localStorage.setItem("permissionStack", JSON.stringify(permissionStack));
             }
-          AuthStore.dispatch({ type: 'loadpermission', payload: permissionStack});
+            if (permissionStack !== null) {
+                AuthStore.dispatch({ type: 'loadpermission', payload: permissionStack });
+            }
         return permissionStack;
     },
     async getAPIBasedPermission() {