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

--- emacs-24.3/configure	2013-03-14 17:42:26.000000000 +0100
+++ emacs-24.3/configure	2013-03-14 17:42:58.000000000 +0100
@@ -26463,7 +26463,7 @@ done
  ;;
     "epaths":C)
 echo creating src/epaths.h
-${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force
+${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force SHELL="$CONFIG_SHELL"
  ;;
     "gdbinit":C)
 if test ! -f src/.gdbinit && test -f $srcdir/src/.gdbinit; then
