http resume: skip body if http code 416 (range error) is ignored.

This avoids appending error data to already existing good data.

Test 92 is updated to match this change.
New test 1156 checks all combinations of --range/--resume, --fail,
Content-Range header and http status code 200/416.

Fixes #1163
Reported-By: Ithubg on github
Closes #2578