Fixed error information being obscured when joining teams with API v4 (#6751)

app/team.go

@@ -199,12 +199,12 @@ func AddUserToTeamByHash(userId string, hash string, data string) (*model.Team,
 	props := model.MapFromJson(strings.NewReader(data))
 
 	if hash != utils.HashSha256(fmt.Sprintf("%v:%v", data, utils.Cfg.EmailSettings.InviteSalt)) {
-		return nil, model.NewLocAppError("JoinUserToTeamByHash", "api.user.create_user.signup_link_invalid.app_error", nil, "")
+		return nil, model.NewAppError("JoinUserToTeamByHash", "api.user.create_user.signup_link_invalid.app_error", nil, "", http.StatusBadRequest)
 	}
 
 	t, timeErr := strconv.ParseInt(props["time"], 10, 64)
 	if timeErr != nil || model.GetMillis()-t > 1000*60*60*48 { // 48 hours
-		return nil, model.NewLocAppError("JoinUserToTeamByHash", "api.user.create_user.signup_link_expired.app_error", nil, "")
+		return nil, model.NewAppError("JoinUserToTeamByHash", "api.user.create_user.signup_link_expired.app_error", nil, "", http.StatusBadRequest)
 	}
 
 	tchan := Srv.Store.Team().Get(props["id"])