convert: raise Abort instead of NoRepo when CVS pserver auth fails.
At this point we know the source is CVS, so we should not go through
the rest of the converters.
adding da/foo
adding foo
% manifest
200 Script output follows
drwxr-xr-x da
-rw-r--r-- 4 foo
200 Script output follows
-rw-r--r-- 4 foo