x forwarded for CURL debug line

curl_it.sh

curl \
      -v \
      -XPOST \
      -H 'Accept: application/vnd.xing.welcome.v1+json' \
      -H 'Authorization: APIKEY api_key="d6b7f10739876f82411106d532655292707477d6"' \
      -H "Content-Type: application/json" \
      -H "X-Forwarded-For: 197.88.46.162, 10.8.33.103" \
      -d '{      
      "first_name":  "xforwardedfor",
      "last_name":   "bug",
      "email":       "xforwardedforbug3@gnix.com",
      "password":    ".test.",
      "tandc_check": "1",
      "language":    "de"
    }' 'https://api.preview.xing.com/vendor/welcome/mobile_signup/users'
    
# see warning appear here
# http://logjam.xing.com/2016/06/27/errors?app=welcome&auto_refresh=0&env=preview&error_type=logged_warning&page=&time_range=date