Page display abnormal when trying to set first page of the site to Link to URL type.

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 M3
• Fix Version/s: 6.2.2 CE GA3 , 6.2.X EE, 7.0.0 M1
• Component/s: Pages > Page Administration, Sites Administration > Sites
• Labels:
  • liferay-fixpack-wcm-core-10-6210
• Environment: Tomcat 7.0 + MySQL 5. Portal master GIT ID: f5ddbaf9c65d4eca0ed3d968be8dc767eeffb824.
• Branch Version/s:
  6.2.x
• Backported to Branch:
  Committed
• Story Points: 5
• Fix Priority: 4
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/16356

1. Add a blank site and Click Site Pages.
2. Add a page and select type to Link to URL.
3. Fill in a URL and Save.

Expected result:
It should be display "The first page cannot be of type Link to URL. " in a pop-up window.

Actual result:
Page display abnormal.