Host header/cache lookup entry doesn't match remap.config perfectly

If I had this in my remap.config

map http://a.com http://b.com:80

The Host header and the cache key constructed by TS had the ":80" in the string based on the incoming request. If the incoming request explicitly specified ":80", then the cache key/host header would also have it. We should construct the cache key/host header exactly as specified in the remap.config