Fix copy/paste error for getting users (#5373)

app/user.go

@@ -389,8 +389,8 @@ func GetUsers(offset int, limit int) ([]*model.User, *model.AppError) {
 	}
 }
 
-func GetUsersMap(page int, perPage int, asAdmin bool) (map[string]*model.User, *model.AppError) {
-	users, err := GetUsers(page*perPage, perPage)
+func GetUsersMap(offset int, limit int, asAdmin bool) (map[string]*model.User, *model.AppError) {
+	users, err := GetUsers(offset, limit)
 	if err != nil {
 		return nil, err
 	}