Browsing Irish translation

This can happen if the user put "-rpath,a" on the command
line.  (Or something similar.  The comma is important).
Getopt becomes confused and thinks that this is a -r option
but it cannot parse the text after the -r so it refuses to
increment the optind counter.  Detect this case and issue
an error message here.  We cannot just make this a warning,
increment optind, and continue because getopt is too confused
and will seg-fault the next time around.