Make sure the right shell is used when creating src/epaths.h.

--- emacs-24.2/configure	2013-01-13 17:01:53.000000000 +0100
+++ emacs-24.2/configure	2013-01-13 17:01:57.000000000 +0100
@@ -24135,7 +24135,7 @@ done
  ;;
     "epaths":C)
 echo creating src/epaths.h
-${MAKE-make} epaths-force
+${MAKE-make} epaths-force SHELL="$CONFIG_SHELL"
  ;;
     "gdbinit":C)
 if test ! -f src/.gdbinit && test -f $srcdir/src/.gdbinit; then