rbinstall.rb: fix timing to read stub
$cmdtype
$script_installer
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
rbinstall.rb: fix timing to read stub
demand. as
$cmdtype
is set to "exe" in parse_args, it is notset yet when
$script_installer
is defined.git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e