Makefile.sub: gem_prelude to load rubygems

* win32/Makefile.sub (DEFAULT_PRELUDES): always use gem_prelude
  regardless of --disable-rubygems.  follow up r43278.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43282 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

win32/Makefile.sub

@@ -291,11 +291,7 @@ BTESTRUBY = $(MINIRUBY)
 !ifndef RUBY
 RUBY = ruby
 !endif
-!if "$(USE_RUBYGEMS)" == "NO"
-DEFAULT_PRELUDES = $(NO_GEM_PRELUDE)
-!else
-DEFAULT_PRELUDES = $(YES_GEM_PRELUDE)
-!endif
+DEFAULT_PRELUDES = $(GEM_PRELUDE)
 
 DTRACE_EXT = dmyh