Fix broken link.

(It needs to be absolute not relative.)

Test: N/A
Change-Id: I7f5b224250b3ba09cda6126b3495adfbc417d2b4

README.md

@@ -197,4 +197,4 @@ Cheatsheet:
 
 If you have any questions or feedback, contact [acloud@google.com](mailto:acloud@google.com).
 
-If you have any bugs or feature requests, [go/acloud-bug](go/acloud-bug).
+If you have any bugs or feature requests, [go/acloud-bug](http://go/acloud-bug).