0.16.0 broke a test in typhoeus

[dblock]

Coming from typhoeus/typhoeus#710 looks like 0.16.0 broke a test in Typhoeus, which was likely not intended.

da1a541

da1a541#commitcomment-107256113

Not quite sure whether the new behavior is intended or whether it's a regression.

[voxik]

@felipedmesquita would you have a chance to look into this issue, please?

[felipedmesquita]

Working on it in my fork felipedmesquita#13, but don't have an ETA on this yet. The fix there currently passes all tests is both ethon and typhoeus, but I need to further investigate weird/broken headers people might receive in the wild to ensure the fix does not break anything else.