Clarify the master branch release instructions.

doc/release/master.md

 # How to push GitLab CE master branch to all remotes.
 
-Distribution to other repo's is done by the lead developer if there is no rush.
+The source code of GitLab is available on multiple servers (with GitLab.com as the canonical source).
+Synchronization between the repo's is done by the lead developer if there is no rush.
 This happens a few times per workday on average.
-If a GitLab B.V. person wants to do it here are the instructions.
+If somebody else with access to all repo's wants to do it the instructions are below.
+This is just to distribute changes, not to make them.
 
 ## Add this to `.bashrc` or [your dotfiles](https://github.com/dosire/dotfiles/commit/52803ce3ac60d57632164b7713ff0041e86fa26c)