Add []s around user@ipv6addr (e.g., "[git@::1]/repo.git")

config/initializers/1_settings.rb

@@ -12,10 +12,14 @@ class Settings < Settingslogic
     def build_gitlab_shell_ssh_path_prefix
       if gitlab_shell.ssh_port != 22
         "ssh://#{gitlab_shell.ssh_user}@#{gitlab_shell.ssh_host}:#{gitlab_shell.ssh_port}/"
+      else
+        if gitlab_shell.ssh_host.include? ':'
+          "[#{gitlab_shell.ssh_user}@#{gitlab_shell.ssh_host}]:"
         else
           "#{gitlab_shell.ssh_user}@#{gitlab_shell.ssh_host}:"
         end
       end
+    end
 
     def build_gitlab_url
       custom_port = gitlab_on_standard_port? ? nil : ":#{gitlab.port}"