Fix default Gitaly binary path

The Gitaly bin dir moved into the root directory:

https://gitlab.com/gitlab-org/gitlab-development-kit/merge_requests/960
https://gitlab.com/gitlab-org/gitlab-development-kit/merge_requests/1028

Right now this path is used by remote mirrors.

config/gitlab.yml.example

@@ -916,7 +916,7 @@ production: &base
   # Gitaly settings
   gitaly:
     # Path to the directory containing Gitaly client executables.
-    client_path: /home/git/gitaly/bin
+    client_path: /home/git/gitaly
     # Default Gitaly authentication token. Can be overridden per storage. Can
     # be left blank when Gitaly is running locally on a Unix socket, which
     # is the normal way to deploy Gitaly.