Fixes homepage preference for new tab when it's opened with a keyboard

Resolves #8278

Auditors: @bsclifton

Test Plan:
- Open preferences, set homepage value
- Set new tab to open homepage
- Open a new tab with a keyboard (cmd+t)

app/common/commonMenu.js

@@ -75,7 +75,6 @@ module.exports.newTabMenuItem = (openerTabId) => {
     click: function (item, focusedWindow) {
       ensureAtLeastOneWindow(Immutable.fromJS({}))
       appActions.createTabRequested({
-        url: 'about:newtab',
         windowId: getCurrentWindowId(),
         openerTabId
       })