If you're using the horrendous `compose.keycloak2.yml` (as creator of this
horrible hack, I am allowed to call it horrendous ;)), you will need to
re-check the new ~/.abra/recipes/matrix-synapse/.env.sample, there are some new
default env vars which you'll have to add in (e.g. KEYCLOAK2_ID=...).

You'll also need to add `KEYCLOAK_ID=keycloak` if using `compose.keycloak.yml`,
it isn't vendored any more.

@decentral1se