Remove dead link to Google Drive

doc/university/README.md

@@ -28,7 +28,6 @@ The curriculum is composed of GitLab videos, screencasts, presentations, project
 #### 1.1. Version Control and Git
 
 1. [Version Control Systems](https://docs.google.com/presentation/d/16sX7hUrCZyOFbpvnrAFrg6tVO5_yT98IgdAqOmXwBho/edit#slide=id.g72f2e4906_2_29)
-1. [Operating Systems and How Git Works](https://drive.google.com/a/gitlab.com/file/d/0B41DBToSSIG_OVYxVFJDOGI3Vzg/view?usp=sharing)
 1. [Code School: An Introduction to Git](https://www.codeschool.com/account/courses/try-git)
 
 #### 1.2. GitLab Basics