Add the automake distdir to POTFILES.skip so that a make distcheck
followed by a failed make distcheck doesn't fail with
[...]
gimp-2.7.2/tools/gimp-remote-x11.c
gimp-2.7.2/tools/gimp-remote.c
If some of these files are left out on purpose then please add them to
POTFILES.skip instead of POTFILES.in. A file 'missing' containing this list
of left out files has been written in the current directory.