Update an external feed

Example request

{
  "name": "New feed",
  "url": "http://requestb.in/173lyyx1",
  "username": "user",
  "password": "password",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c",
  "headers": [
    {
      "name": "header1",
      "value": "value1"
    },
    {
      "name": "header2",
      "value": "value2"
    }
  ],
  "maxRetries": 5,
  "cache": true
}