[Etherpad] Oops, forgot that week instances uses PGSQL

pica-etherpad/docker-compose.yml

@@ -92,7 +92,7 @@ services:
       - week
 
   etherpad-week-db:
-    image: registry.picasoft.net/pica-etherpad-db:mysql8.picapatch2
+    image: postgres:12
     container_name: etherpad-week-db
     security_opt:
       - no-new-privileges
@@ -100,10 +100,8 @@ services:
     cpus: "0.40"
     pids_limit: 1024
     volumes:
-      - weekpad-db:/var/lib/mysql
+      - weekpad-db:/var/lib/postgresql/data
     env_file: ./secrets/etherpad-week-db.secrets
     restart: unless-stopped
-    # See https://stackoverflow.com/questions/41134785/how-to-solve-mysql-warning-innodb-page-cleaner-1000ms-intended-loop-took-xxx
-    command: --innodb_lru_scan_depth=128 --default-authentication-plugin=mysql_native_password
     networks:
       - week

pica-etherpad/settings_week.json

@@ -6,10 +6,10 @@
   "ip": "${IP:0.0.0.0}",
   "port": "${PORT:8080}",
   "showSettingsInAdminPage": "${SHOW_SETTINGS_IN_ADMIN_PAGE:true}",
-  "dbType": "${DB_TYPE:mysql}",
+  "dbType": "${DB_TYPE:postgres}",
   "dbSettings": {
     "host":     "${DB_HOST}",
-    "port":     "${DB_PORT:3306}",
+    "port":     "${DB_PORT:5432}",
     "database": "${DB_NAME}",
     "user":     "${DB_USER}",
     "password": "${DB_PASSWORD}",