Remove rapi-user and rapi-pass from qa-sample.json

After commit 725ec2f1 they are unused.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

qa/qa-sample.json

@@ -6,9 +6,6 @@
   "os": "debian-etch",
   "mem": "512M",
 
-  "rapi-user": "foobar",
-  "rapi-pass": "barfoo",
-
   "# Lists of disk sizes": null,
   "disk": ["1G", "512M"],
   "disk-growth": ["2G", "768M"],