Configure wiki display portlet incorrectly

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: Master
• Component/s: Wiki
• Labels: None
• Story Points: 3
• Fix Priority: 3
• Sprint: LIMA | QA Sprint 1
• Git Pull Request: https://github.com/liferay-lima/liferay-portal/pull/1028

Steps to reproduce:

1. Create a new wiki page under Main Wiki
2. Create a widget page > Add a Wiki Display portlet on it
3. Try to Configure the Wiki Display portlet to display the wiki page previously created

Expected Result:
Configure wiki display portlet correctly - After saved the Main node, then you can select the wiki page in the same iframe.

Actual Result:
Configure wiki display portlet incorrectly - After saved the Main node, the page selection is not displayed, the frontpage displays in a new iframe.