Undo duplicate line

Author: paulvdbles

CONTRIBUTING.md

@@ -15,7 +15,6 @@ Contributions to this project must be accompanied by a Contributor License
 Agreement. You (or your employer) retain the copyright to your contribution;
 this simply gives us permission to use and redistribute your contributions as
 part of the project. Head over to <https://cla.developers.google.com/> to see
-part of the project. Head over to <https://cla.developers.google.com/> to see
 your current agreements on file or to sign a new one.
 
 You generally only need to submit a CLA once, so if you've already submitted one