fixup for 0904dfee8f: fix loading of localfiles from tests
fixup for 0904dfee8f: fix loading of localfiles from tests

appsuite might be located in different base directories. /appsuite/ is
used on local development machines (those using appserver); /base/ is
used by tests running on karma web server. In both cases localfiles must
strip the base directory from the path of the url, to lookup the files
locally. This should now be more robust.

Open-Xchange-Frontend/appserver