Merge pull request #100 from opencloud-eu/pin_postgres_version

quick fix for breaking changes in postgres 18 by pinning to 17

idm/ldap-keycloak.yml

@@ -65,7 +65,7 @@ services:
     restart: always
 
   postgres:
-    image: postgres:alpine
+    image: postgres:17-alpine
     networks:
       opencloud-net:
     volumes:

testing/external-keycloak.yml

@@ -1,7 +1,7 @@
 ---
 services:
   postgres:
-    image: postgres:alpine
+    image: postgres:17-alpine
     networks:
       opencloud-net:
     volumes: