Doc: Add the need to upgrade to Go 1.8.3 in the 9.1->9.2 documentation as the...

Doc: Add the need to upgrade to Go 1.8.3 in the 9.1->9.2 documentation as the upgrade fails with Go 1.5 (installed with Gitlab 8.1)

doc/update/9.1-to-9.2.md

@@ -110,8 +110,8 @@ sudo -u git -H bin/compile
 ### 7. Update gitlab-workhorse
 
 Install and compile gitlab-workhorse. This requires
-[Go 1.5](https://golang.org/dl) which should already be on your system from
-GitLab 8.1. GitLab-Workhorse uses [GNU Make](https://www.gnu.org/software/make/).
+[Go 1.8](https://golang.org/dl). Go (at least 1.5) should already be on your system from
+GitLab 8.1 and shall be upgraded if necessary. Please note that starting in Gitlab 9.3, only Go 1.8.3 and above will be supported. GitLab-Workhorse uses [GNU Make](https://www.gnu.org/software/make/).
 If you are not using Linux you may have to run `gmake` instead of
 `make` below.