ruby.pc.in: reorder

* template/ruby.pc.in: reorder library flags which may refer library
  names.  [Bug #7913]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39393 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-02-23

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39394 b2dd03c8-39d4-4d8f-98ff-823fe69b080e