'bash-minimal' is a package derived from 'bash' package. 'bash-minimal'
is supposed to override keywords from 'bash', but does not do it due to
ordering issue.
This patch moves #:modules last.
Fixes the bootstrap failure reported by rennes and Manolis Ragkousis and
tracked down by Andy Wingo in
<https://lists.gnu.org/archive/html/guix-devel/2017-05/msg00010.html>.
* gnu/packages/bash.scm (bash-minimal)[arguments]: Move #:modules
after (package-arguments bash).
Signed-off-by: Ludovic Courtès <ludo@gnu.org>