[stable9] Make sure the UID is correctly cased

[nickvergessen]

Backport of #1766 #1142

@MorrisJobke @LukasReschke

[mention-bot]

@nickvergessen, thanks for your PR! By analyzing the history of the files in this pull request, we identified @DeepDiver1975 and @carlaschroder to be potential reviewers.

[MorrisJobke]

I tested this and it only works with lower case user names. If I try ./occ files:transfer-ownership Test1 Test it still shows the wrong casing:

Analysing files of Test1 ...
    1 [============================]
Collecting all share information for files and folder of Test1 ...
    0 [>---------------------------]
Transferring files to Test2/files/transferred from Test1 on 2016-10-17T15:45:28+00:00 ...
Restoring shares ...
    0 [>---------------------------]

[MorrisJobke]

If I try ./occ files:transfer-ownership Test1 Test it still shows the wrong casing:

to clarify: The user names are lower case in Nextcloud. The files are not transfered and the output also shows the reason: the casing is somehow still wrong.

[nickvergessen]

Added backport of #1142 now it works.

[MorrisJobke]

Tested and works now 👍

cc @rullzer please review

[rullzer]

Yep.
LGTM!