Only update Vue router if changed

It looke like this now throws an error when
`router.push(...)` is called with current path.

spec/frontend/ide/sync_router_and_store_spec.js

@@ -17,9 +17,13 @@ describe('~/ide/sync_router_and_store', () => {
 
   const getRouterCurrentPath = () => router.currentRoute.fullPath;
   const getStoreCurrentPath = () => store.state.router.fullPath;
-  const updateRouter = path => {
+  const updateRouter = async path => {
+    if (getRouterCurrentPath() === path) {
+      return;
+    }
+
     router.push(path);
-    return waitForPromises();
+    await waitForPromises();
   };
   const updateStore = path => {
     store.dispatch('router/push', path);