always require OIDC_OP_ISSUER and OIDC_OP_SESSION_SECRET to be set when using compose

docker-compose.yml

@@ -6,8 +6,8 @@ services:
     ports:
       - "8000:8000"
     environment:
-      OIDC_OP_ISSUER: "http://localhost:8000"
-      OIDC_OP_SESSION_SECRET: "change-me-in-production"
+      OIDC_OP_ISSUER: "${OIDC_OP_ISSUER:?set OIDC_OP_ISSUER to the public HTTPS URL}"
+      OIDC_OP_SESSION_SECRET: "${OIDC_OP_SESSION_SECRET:?set OIDC_OP_SESSION_SECRET to a random secret}"
     volumes:
       - app-data:/app/data
     profiles: