don't empty urlbar when focused

fix #4851

Auditors: @bbondy

Test Plan:
1. go to any site
2. click on the webview
3. hit cmd+L
4. verify that the urlbar is selected and is not blank

js/components/urlBar.js

@@ -291,7 +291,6 @@ class UrlBar extends ImmutableComponent {
   componentWillMount () {
     ipc.on(messages.SHORTCUT_FOCUS_URL, (e) => {
       // If the user hits Command+L while in the URL bar they want everything suggested as the new potential URL to laod.
-      windowActions.setUrlBarActive(true)
       this.updateLocationToSuggestion()
       windowActions.setUrlBarSelected(true)
       // The urlbar "selected" might already be set in the window state, so subsequent Command+L won't trigger component updates, so this needs another DOM refresh for selection.

test/components/navigationBarTest.js

@@ -674,6 +674,16 @@ describe('navigationBar', function () {
           return this.getAttribute(activeWebview, 'src').then((src) => src === page1)
         })
       })
+
+      it('urlbar shows webview url when focused', function * () {
+        var page1 = this.page1
+        yield blur(this.app.client)
+        yield this.app.client
+          .ipcSend('shortcut-focus-url')
+        yield this.app.client.waitUntil(function () {
+          return this.getValue(urlInput).then((val) => val === page1)
+        })
+      })
     })
 
     describe('with non-url input value', function () {