Replaced 127.0.0.1 with %HOSTIP where possible

tests/data/test15

@@ -42,14 +42,14 @@ Fake: yes
 Content-Length: 26
 
 Repeated nonsense-headers
-http://127.0.0.1:%HTTPPORT/want/15 200 26
+http://%HOSTIP:%HTTPPORT/want/15 200 26
 </stdout>
 <strip>
 ^User-Agent:.*
 </strip>
 <protocol>
 GET /want/15 HTTP/1.1
-Host: 127.0.0.1:%HTTPPORT
+Host: %HOSTIP:%HTTPPORT
 Accept: */*
 
 </protocol>