fix wrong secret reference in Makefile

Author: xetys

Makefile

@@ -16,7 +16,7 @@ test:
 		 -e TEST_ZONE_NAME=$$TEST_ZONE_NAME \
 		 -e OS_TENANT_NAME=$$OS_TENANT_NAME \
 		 -e OS_TENANT_ID=$$OS_PROJECT_ID \
-		 -e OS_DOMAIN_NAME=$$OS_USER_DOMAIN_NAME \
+		 -e OS_DOMAIN_NAME=$$OS_DOMAIN_NAME \
 		 -e OS_USERNAME=$$OS_USERNAME \
 		 -e OS_PASSWORD=$$OS_PASSWORD \
 		 -e OS_AUTH_URL=$$OS_AUTH_URL \