gnu: bash-minimal: Override keywords from 'bash'.

'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>

gnu/packages/bash.scm

@@ -211,11 +211,11 @@ without modification.")
     (outputs (delete "include" (package-outputs bash)))
 
     (arguments
-     (let ((args `(#:modules ((guix build gnu-build-system)
+     (let ((args `(,@(package-arguments bash)
+                   #:modules ((guix build gnu-build-system)
                               (guix build utils)
                               (srfi srfi-1)
-                              (srfi srfi-26))
-                   ,@(package-arguments bash))))
+                              (srfi srfi-26)))))
        (substitute-keyword-arguments args
          ((#:configure-flags flags)
           `(list "--without-bash-malloc"