* add trivial clarification about jemalloc

* switch from google.com to recaptcha.net

because https://developers.google.com/recaptcha/docs/faq#can-i-use-recaptcha-globally

Log tracebacks correctly

Fix backfill storing incorrect state for events

MSC 1866 - Use M_UNSUPPORTED_ROOM_VERSION for invite API

Handle errors when fetching remote server keys

Correctly proxy exception in frontend_proxy worker

Fix up pusher logging a bit

Fix state cache invalidation on workers

Make sure that users' changes to the config files are preserved.

Fixes #4440.

We're counting the number of push notifications, but not the number of badges;
I'd like to see if they are significant.

* You need an entry in the debian changelog (and not a regular newsfragment)
  for debian packaging changes.
* Regular newsfragments must end in full stops.

I suspect the CPU usage metrics for this are going to /dev/null at the moment.

* Added HAProxy example

Proposal of an example with HAProxy. Asked by #4541.

Signed-off-by: Benoît S. (“Benpro”) <gitlab@benpro.fr>

* Following suggestions of @richvdh

Prevent crash on pagination.

Migration Script: consider e2e_room_keys.is_verified column as boolean