Different homepage depending on login status for public wiki-only projects
### Summary
The front-page of a wiki-only project is not the same for logged-in and non-logged users.
### Steps to reproduce
- Create a **public** project
- In the settings under *Permissions*, disable everything except *Wiki*
- Create a wiki homepage in the project
### Example Project
https://gitlab.com/ryancey/issue-wikiproject
### What is the current *bug* behavior?
A different project homepage is displayed depending on the login status :
- For **logged in** users, the **wiki homepage** is displayed as the project homepage.
- For **non-logged** users, the **activity feed** is displayed as the project homepage.
### What is the expected *correct* behavior?
The same homepage should be displayed for every users, in this case the wiki homepage.
### Relevant logs and/or screenshots
**Logged-in users** (should be the correct behavior)

**Non-logged users**

issue