Steps to reproduce:

1. Create webhook with the following code:
   

   var response,
       request = new CurlHttpRequest(),
       url = 'https://postman-echo.com/get';
    
   request.AddHeader('Custom-header: 12345');
   response = request.Get(url);
   
   return response;

2. Execute test from Frontend.
3. Observe that webhook returns '1'
4. Change webhook code to the following:
   

   var response,
       request = new CurlHttpRequest(),
       url = 'https://postman-echo.com/get';
    
   request.AddHeader('Custom-header: 12345');
   response = request.Get(url, '');
   
   return response;

5. Observe that webhook returns expected result:
   

   var response,{
       "args": {},
       "headers": {
           "x-forwarded-proto": "https",
           "host": "postman-echo.com",
           "accept": "*\/*",
           "content-type": "application\/x-www-form-urlencoded",
           "custom-header": "12345",
           "x-forwarded-port": "443"
       },
       "url": "https:\/\/postman-echo.com\/get"
   }

Expected:
It is expected for HTTP requests to not have required empty data field.