fix(nginx): environment au format tableau attendu par Runtipi

Le schéma v2 de Runtipi refuse environment sous forme d'objet (erreur « services[0].environment must be an array »). Revient au format [{key, value}] utilisé avant le commit d24d0c1.

apps/nginx/docker-compose.json

@@ -29,10 +29,16 @@
           "readOnly": true
         }
       ],
-      "environment": {
-        "NGINX_HOST": "${NGINX_SERVER_NAME:-localhost}",
-        "TZ": "${TZ:-Europe/Paris}"
+      "environment": [
+        {
+          "key": "NGINX_HOST",
+          "value": "${NGINX_SERVER_NAME:-localhost}"
         },
+        {
+          "key": "TZ",
+          "value": "${TZ:-Europe/Paris}"
+        }
+      ],
       "healthCheck": {
         "test": "curl --fail http://localhost:80 || exit 1",
         "interval": "30s",