Photos 4.1rc4

I decided to do one :scare: final :/scare: release candidate of Photos 4.1 to make sure I’ve gotten everything fixed up. The PHP notices people were seeing should be fixed and there haven’t been other reports (yet) of more strings that need to be translated.

I would recommend people use this version instead of 4.0.1 as it fixes a number of issues that were in 4.0.1.