redirect-test: remove a flaky test
redirect-test: remove a flaky test

Bug 651446 involved a race condition when queuing a message while
another message was being redirected on the same host. The fix
included a regression test, but later rewrites of SoupSession made the
race condition no longer possible, and made the test itself slightly
flaky. So just remove it.

jwendell/libsoup,jwendell/libsoup,fanc999/libsoup,jwendell/libsoup,fanc999/libsoup,fanc999/libsoup,jwendell/libsoup,fanc999/libsoup,jwendell/libsoup,fanc999/libsoup