Merge branch 'vp/http-rate-limit-retries'

The HTTP transport learned to react to "429 Too Many Requests".

* vp/http-rate-limit-retries:
  http: add support for HTTP 429 rate limit retries
  strbuf_attach: fix call sites to pass correct alloc
  strbuf: pass correct alloc to strbuf_attach() in strbuf_reencode()

diff --cc builtin/am.c
Simple merge

diff --cc builtin/fast-import.c
Simple merge

diff --cc http.c
Simple merge

diff --cc mailinfo.c
Simple merge

diff --cc refs/files-backend.c
Simple merge

diff --cc remote-curl.c
Simple merge

diff --cc strbuf.c
Simple merge

diff --cc t/lib-httpd.sh
Simple merge

diff --cc t/lib-httpd/apache.conf
Simple merge

diff --cc t/meson.build
Simple merge

diff --cc trailer.c
Simple merge