Post work for #2637

Improve test cases, config settings, also show SSH config settings on admin config panel.

routers/admin/admin.go

@@ -204,6 +204,8 @@ func Config(ctx *middleware.Context) {
 	ctx.Data["ScriptType"] = setting.ScriptType
 	ctx.Data["ReverseProxyAuthUser"] = setting.ReverseProxyAuthUser
 
+	ctx.Data["SSH"] = setting.SSH
+
 	ctx.Data["Service"] = setting.Service
 	ctx.Data["DbCfg"] = models.DbCfg
 	ctx.Data["Webhook"] = setting.Webhook