ldap-sync: fix creation of only one user per LDAP sync (#375)

Before this fix, a too early `return` statement terminated the
`updateLdapUsers()` function, whenever one not already existing user was
created. Therefore, in each LDAP sync a maximum of one new user could be
created (i.e., it took x LDAP sync cycles until x new LDAP users are
registered in wg-portal). Depending on the LDAP `sync_interval` this can
take a long time and produces unecessary long waiting times until users
are available in wg-portal.

Removing the early return statement, and move the remainder of the
function into an `else` statement, so that all new users can be
added in a single LDAP sync.

Also adding a debug statement to better trace the behavior.

Signed-off-by: klmmr <35450576+klmmr@users.noreply.github.com>

internal/app/users/user_manager.go

@@ -506,18 +506,16 @@ func (m Manager) updateLdapUsers(
 		tctx, cancel := context.WithTimeout(ctx, 30*time.Second)
 		tctx = domain.SetUserInfo(tctx, domain.SystemAdminContextUserInfo())
 
-		// create new user
 		if existingUser == nil {
+			// create new user
+			logrus.Tracef("creating new user %s from provider %s...", user.Identifier, provider.ProviderName)
+			
 			err := m.NewUser(tctx, user)
 			if err != nil {
 				cancel()
 				return fmt.Errorf("create error for user id %s: %w", user.Identifier, err)
 			}
-
+		} else {
-			cancel()
-			return nil
-		}
-
 			// update existing user
 			if provider.AutoReEnable && existingUser.DisabledReason == domain.DisabledReasonLdapMissing {
 				user.Disabled = nil
@@ -552,6 +550,7 @@ func (m Manager) updateLdapUsers(
 					m.bus.Publish(app.TopicUserEnabled, *user)
 				}
 			}
+		}
 
 		cancel()
 	}