no-jira: reduce level of user sync to WARN by LDAP

src/main/java/org/olat/ldap/manager/LDAPLoginManagerImpl.java

@@ -592,11 +592,11 @@ public class LDAPLoginManagerImpl implements LDAPLoginManager, AuthenticationPro
 		String email = getAttributeValue(userAttributes.get(syncConfiguration.getOlatPropertyToLdapAttribute(UserConstants.EMAIL)));
 		// Lookup user
 		if (securityManager.findIdentityByLogin(uid) != null) {
-			log.error("Can't create user with username='{}', this username does already exist in the database", uid);
+			log.warn("Can't create user with username='{}', this username does already exist in the database", uid);
 			return null;
 		}
 		if(!securityModule.isIdentityNameAutoGenerated() && securityManager.findIdentityByName(uid) != null) {
-			log.error("Can't create user with username='{}', this identity name does already exist in the database", uid);
+			log.warn("Can't create user with username='{}', this identity name does already exist in the database", uid);
 			return null;
 		}
 		if(StringHelper.containsNonWhitespace(email) || userModule.isEmailMandatory()) {
@@ -606,7 +606,7 @@ public class LDAPLoginManagerImpl implements LDAPLoginManager, AuthenticationPro
 				return null;
 			}
 			if (!userManager.isEmailAllowed(email)) {
-				log.error("Can't create user {} with email='{}', a user with that email does already exist in the database", uid, email);
+				log.warn("Can't create user {} with email='{}', a user with that email does already exist in the database", uid, email);
 				return null;
 			}
 		}