We do not care about the json:{} filenames here, so we can just filter
them out and thus make the test work both with and without external data
files.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: 20191107163708.833192-21-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>