Makefile.sub: configurations

* win32/Makefile.sub (prog): needs to update configurations.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39999 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

win32/Makefile.sub

@@ -382,6 +382,7 @@ ECHO_BEGIN = @echo.
 ECHO_END =
 
 all: $(srcdir)/win32/Makefile.sub $(win_srcdir)/Makefile.sub $(srcdir)/common.mk
+prog: config
 
 ruby: $(PROGRAM)
 rubyw: $(WPROGRAM)