Fix test for changes in httpbin.org
Fix test for changes in httpbin.org

It sends an X-Processed-Time header now. But silence no. 1277 instead of
including it into the expected report, because the title of no. 1277
has changed on HTTPolice master, so it's hard to write the assertion
correctly.

vfaronov/mitmproxy-httpolice,vfaronov/mitmproxy-httpolice