fixes: correct users importing id (#645)

@princemaple could you try out this branch to see if it works on your end?

cmd/users_import.go

@@ -70,6 +70,10 @@ list or set it to 0.`,
 						checkErr(usernameConflictError(user.Username, conflictuous.ID, user.ID))
 					}
 				}
+			} else {
+				// If it doesn't exist, set the ID to 0 to automatically get a new
+				// one that make sense in this DB.
+				user.ID = 0
 			}
 
 			err = d.store.Users.Save(user)

storage/bolt/importer/users.go

@@ -55,7 +55,6 @@ func convertUsersToNew(old []*oldUser) ([]*users.User, error) {
 
 	for _, oldUser := range old {
 		user := &users.User{
-			ID:           uint(oldUser.ID),
 			Username:     oldUser.Username,
 			Password:     oldUser.Password,
 			Scope:        oldUser.Scope,