Swift tests for unicode headers

Swift functional tests sends ilegal headers (unicode) and expects
these headers to be processed by Swift.

Apache2 seem to remove such headers which is a sound behavior for
illegal headers.

This change restrict the test tpo exist only for swift integral
web front end. For future it is advised to disallow such behaviour.
For example it is suggested to make the decission that in future APIs
illegal headers are removed rather than processed.

Change-Id: Ibf548f474de3f06a2687f8f4812beaeaf81ab216
Fixes: Bug #1189123
Merge "Swift tests for unicode headers"