Remove an internal link that wasn't getting stripped correctly.

RELNOTES: n/a
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114364089

Author: shicks

CONTRIBUTING

@@ -1,12 +1,5 @@
 Closure Library welcomes patches/pulls for features and bugfixes.
 
-<!-- MOE:begin_strip -->
-
-For contributors inside Google, follow the instructions given here:
-http://go/closure-contributors
-
-<!-- MOE:end_strip -->
-
 For contributors external to Google, follow the instructions given here:
 
 Notes on Contributions to Closure Library
@@ -49,4 +42,4 @@ clearer). In this case, the issue associated with the pull request
 will be closed when the patch pushed to the repository via the MOE
 (Make Open Easy) system.
 
-https://code.google.com/p/moe-java/
+https://github.com/google/MOE/