Fixed typos

docker-compose.yml

         ports:
             - "127.0.0.1:35081:80"
         environment:
-          POSTGRES_DB: nextcloud
+          - POSTGRES_DB=nextcloud
         env_file:
             - env
 

env

 POSTGRES_USER=postgres
 POSTGRES_PASSWORD=change_it
-POSTGRES_HOST=postgresql.nextcloud.internal.docker:5432
+POSTGRES_HOST=postgresql.main.internal.docker:5432
 
 NEXTCLOUD_ADMIN_USER=root
 NEXTCLOUD_ADMIN_PASSWORD=change_it