title: Add "Connected service" in .netStandard2.0 project
body: <p>I would like to add a "connected service" in my .Net Standard 2.0 project (class library) (Visual Studio 2019)</p>
  
  <p>I have a <strong>.wsdl file</strong>. And I tried to add a "connected service" to my project but an error occured : 
  <a href="https://i.stack.imgur.com/FAW2V.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FAW2V.png" alt="enter image description here"></a></p>
  
  <p>When I test to import the same <strong>.wsdl file</strong> in a .netFramework4.5.2 project there is no error and the service is added.</p>
  
  <p>Do you have any idea about the problem ?</p>