enable setting database URL

roles/matrix-bot-maubot/templates/config/config.yaml.j2

@@ -3,10 +3,12 @@
 # Format examples:
 #   SQLite:   sqlite:///filename.db
 #   Postgres: postgresql://username:password@hostname/dbname
-database: sqlite:////data/maubot.db
+database: {{ matrix_bot_maubot_storage_database|to_json }}
 
 # Separate database URL for the crypto database. "default" means use the same database as above.
-crypto_database: default
+crypto_database: 
+    type: default
+    postgres_uri: {{ matrix_bot_maubot_storage_database|to_json }}
 
 # Additional arguments for asyncpg.create_pool() or sqlite3.connect()
 # https://magicstack.github.io/asyncpg/current/api/index.html#asyncpg.pool.create_pool