Fix matrix_postgres_connection_password length check

CHANGELOG.md

@@ -32,7 +32,7 @@ To migrate to the new setup, expect a few minutes of downtime, while you follow
 
 1. We believe the steps below are safe and you won't encounter any data loss, but consider [making a Postgres backup](docs/maintenance-postgres.md#backing-up-postgresql) anyway. If you've never backed up Postgres, now would be a good time to try it.
 
-2. Generate a strong password to be used for your superuser Postgres user (called `matrix`). You can use `pwgen -s 64 1` to generate it, or some other tool.
+2. Generate a strong password to be used for your superuser Postgres user (called `matrix`). You can use `pwgen -s 64 1` to generate it, or some other tool. The **maximum length** for a Postgres password is 100 bytes (characters). Don't go crazy!
 
 3. Update your playbook's `inventory/host_vars/matrix.DOMAIN/vars.yml` file, adding a line like this:
 ```yaml

roles/matrix-postgres/tasks/validate_config.yml

@@ -36,4 +36,4 @@
 - name: Fail if Postgres password length exceeded
   fail:
     msg: "The maximum `matrix_postgres_connection_password` length is 99 characters"
-  when: "matrix_postgres_connection_hostname|length > 99"
+  when: "matrix_postgres_connection_password|length > 99"