Fix issue where you'd get hanging connections, passing a \r into fileIds.

Working with bash it's easier to get a \r in your ids, than not.
Even more so, it's hard to debug when it happens and hangs your HEAD
request.

To reproduce:
git pull
git checkout 6ac7656bec
go run src/cmd/tusd/*.go
./scripts/demo-alphabet.sh

src/cmd/tusd/http.go

@@ -11,7 +11,7 @@ import (
 	"strconv"
 )
 
-var fileRoute = regexp.MustCompile("^/files/([^/]+)$")
+var fileRoute = regexp.MustCompile("^/files/([^/\r\n]+)\r?$")
 var filesRoute = regexp.MustCompile("^/files/?$")
 var dataStore *DataStore