Fix problem with Chrome 33 and empty headers

Chrome 33 can't handle empty headers in WS upgrade responses it seems. The result is an "Invalid UTF-8 sequence in header" error.
Merge pull request #1823 from Artur-/master

Fix problem with Chrome 33 and empty headers
Revert "Fixes #1320 again" and "Add test for #1320"

This reverts commit 4156353df3a4e142d8d87e38cf363c467cb9deaf.
This reverts commit a4c313184b1cbc86b1ec59235bf02c7729c12a0c.