chore: drop the CLA links

Author: Sam Harrison

README.md

@@ -106,7 +106,6 @@ Quick links:
 
 - [Feature Request](https://github.com/sendgrid/csharp-http-client/blob/master/CONTRIBUTING.md#feature-request)
 - [Bug Reports](https://github.com/sendgrid/csharp-http-client/blob/master/CONTRIBUTING.md#submit-a-bug-report)
-- [Sign the CLA to Create a Pull Request](https://github.com/sendgrid/csharp-http-client/blob/master/CONTRIBUTING.md#cla)
 - [Improvements to the Codebase](https://github.com/sendgrid/csharp-http-client/blob/master/CONTRIBUTING.md#improvements-to-the-codebase)
 
 <a name="thanks"></a>