redhat/configs: Fix rm warning on error

When an unset config is found, process_configs.sh cleans up and returns an
error. In this case the .newconfigs file is not created and errors
like

rm: cannot remove '.newoptions18': No such file or directory
rm: cannot remove '.newoptions16': No such file or directory
rm: cannot remove '.newoptions17': No such file or directory

are output to the user.

Since we output the "real" error at the end of the output, these errors
can be safely ignored.

Signed-off-by: Prarit Bhargava prarit@redhat.com