If it feels ok to ride then it's ok. The top tube will be a bit long for you and this may stretch you out but Touring bikes are traditionally generous in the geometry and should be comfortable rather than racing machines. The true test will come when you do a long ride, if it hurts your back then you'll need to re-think, but there's still things you can do like shortening the stem and sliding the saddle forward. We do love a bargain don't we.