add env_vars nobuild

webtrees/config.yaml

@@ -83,6 +83,7 @@ map:
   - ssl
 name: Webtrees
 options:
+  env_vars: []
   BASE_URL: http://192.168.178.23
   DATA_LOCATION: /config/data
   certfile: fullchain.pem
@@ -98,6 +99,9 @@ privileged:
   - SYS_ADMIN
   - DAC_READ_SEARCH
 schema:
+  env_vars:
+    - name: match(^[A-Z0-9_]+$)
+      value: str?
   BASE_URL: url
   DATA_LOCATION: str
   base_url_portless: bool?