fix #345 let nextcloud install create the postgres database

Author: SnowMB

.examples/docker-compose/insecure/postgres/apache/docker-compose.yml

@@ -4,6 +4,8 @@ services:
   db:
     image: postgres
     restart: always
+    environment: 
+      - POSTGRES_DATABASE=not_used
     volumes:
       - db:/var/lib/postgresql/data
     env_file:

.examples/docker-compose/insecure/postgres/fpm/docker-compose.yml

@@ -4,6 +4,8 @@ services:
   db:
     image: postgres
     restart: always
+    environment:
+      - POSTGRES_DATABASE=not_used 
     volumes:
       - db:/var/lib/postgresql/data
     env_file:

.examples/docker-compose/with-nginx-proxy/postgres/apache/docker-compose.yml

@@ -3,7 +3,9 @@ version: '3'
 services:
   db:
     image: postgres
-    restart: always
+    restart: always    
+    environment:
+      - POSTGRES_DATABASE=not_used 
     volumes:
       - db:/var/lib/postgresql/data
     env_file:

.examples/docker-compose/with-nginx-proxy/postgres/fpm/docker-compose.yml

@@ -3,7 +3,9 @@ version: '3'
 services:
   db:
     image: postgres
-    restart: always
+    restart: always    
+    environment:
+      - POSTGRES_DATABASE=not_used
     volumes:
       - db:/var/lib/postgresql/data
     env_file: