If I'm not mistake you'll have to uninstall the default "Photos" application && than reinstall it.
Directions on uninstalling the default Photo's application:
- Type in on the bottom search bar "Powershell" you should "Windows PowerShell"
- Copy this command in without the quotations "Get-AppxPackage *photos* | Remove-AppxPackage"
- Than to reinstall the applications it will be listed in this article that I've found.
Link : http://www.howtogeek.com/224798/how-to-uninstall-windows-10s-built-in-apps-and-how-to-reinstall-them/
Good Luck!