Error rendering thumbnails for screenshots

[Michael Nelson]

We're seeing 300+ errors a day with "IOError: cannot write mode P as JPEG" [1]

The problem and solution are outlined on a similar bug for the easy-thumbnailing plugin [2] (which we don't use, just the same issue - the uploaded PNG uses palette mode, we then try to save a JPEG thumbnail but don't switch the mode, so fail because JPEG doesn't support palettes).

As a work-around, it may be worth updating the screenshots used for manager-accounting [3] to avoid the problem until the fix is deployed (simply uploading JPEG versions of the screenshots would fix it).

[1] https://oops.canonical.com/?oopsid=OOPS-0105c238dbdb4442b0511b1fb8c8732a
[2] https://github.com/SmileyChris/easy-thumbnails/issues/95
[3] https://apps.ubuntu.com/cat/applications/manager-accounting/ (the 500 errors are the reason for the lack of screenshots there).