Merge branch 'js/http-custom-headers'

Update tests for "http.extraHeaders=<header>" to be portable back to Apache 2.2 (the original depended on <RequireAll/> which is a more recent feature). * js/http-custom-headers: submodule: ensure that -c http.extraheader is heeded t5551: make the test for extra HTTP headers more robust tests: adjust the configuration for Apache 2.2