Remove Explore > "New tab" from sidebar

- we don't support tabs yet, might as well remove the entry

pkg/api/index.go

@@ -147,9 +147,6 @@ func (hs *HTTPServer) setIndexViewData(c *m.ReqContext) (*dtos.IndexViewData, er
 			SubTitle: "Explore your data",
 			Icon:     "fa fa-rocket",
 			Url:      setting.AppSubUrl + "/explore",
-			Children: []*dtos.NavLink{
-				{Text: "New tab", Icon: "gicon gicon-dashboard-new", Url: setting.AppSubUrl + "/explore"},
-			},
 		})
 	}