MariaDB server writes warnings into errorlog although 'log_warnings=0'

CREATE TABLE `test_pending` (

  `UniqueEventUnitID` int(11) NOT NULL,

  `LMByHostName` varchar(255) DEFAULT '?',

  `LMByHandlerName` varchar(80) DEFAULT '?',

  `LMByZISUserID` varchar(80) DEFAULT '?',

  `LMByUniqueID` int(11) DEFAULT 0,

  `ModifyTime` datetime DEFAULT '2004-01-01 00:00:00',

  `ModifyCounter` int(11) DEFAULT 0,

  `CreateTime` datetime DEFAULT '2004-01-01 00:00:00',

  `EraseTime` datetime DEFAULT '2004-01-01 00:00:00',

  `EventUnitState` smallint(6) DEFAULT 0,

  `UserDefinedEventUnitID` varchar(80) DEFAULT '',

  `StateText` text DEFAULT NULL,

  `ZISSourceDescData` blob DEFAULT NULL,

  `ZISSourceOTypNr` int(11) DEFAULT 0,

  `ZISSourceRBNr` int(11) DEFAULT 0,

  `AcknowledgeFlag` tinyint(4) DEFAULT 0,

  `RevisionFlag` tinyint(4) DEFAULT 0,

  `RepeatCounter` int(11) DEFAULT 0,

  `HelpFileName` varchar(255) DEFAULT '',

  `HasEventUnitTMOAction` tinyint(4) DEFAULT 0,

  `TMOActionDateTime` datetime DEFAULT NULL,

  `TMOSetAcknowledgeFlag` tinyint(4) DEFAULT NULL,

  `TMONewAcknowledgeFlag` tinyint(4) DEFAULT NULL,

  `TMOSetRevisionFlag` tinyint(4) DEFAULT NULL,

  `TMONewRevisionFlag` tinyint(4) DEFAULT NULL,

  `TMOSetEventUnitState` tinyint(4) DEFAULT NULL,

  `TMONewEventUnitState` smallint(6) DEFAULT NULL,

  `TMOEventUnitTMOAction` tinyint(4) DEFAULT NULL,

  `TMOREXXLabelStartActive` smallint(6) DEFAULT NULL,

  `TMOREXXLabelName` varchar(80) DEFAULT NULL,

  `TMOREXXLabelParams` text DEFAULT NULL,

  `TMOREXXLabelStartBeforeEvtActn` smallint(6) DEFAULT NULL,

  `ProductInterfaceType` tinyint(4) DEFAULT NULL,

  `ProductInterfaceID` varchar(80) DEFAULT NULL,

  `UniqueProductInterfaceEventID` varchar(255) DEFAULT NULL,

  `CreatorZISSourceDescData` blob DEFAULT NULL,

  `CreatorZISSourceOTypNr` int(11) DEFAULT NULL,

  `CreatorZISSourceRBNr` int(11) DEFAULT NULL,

  `Description` text DEFAULT NULL,

  `EventAttributesDictionary` blob DEFAULT NULL,

  `EventAttributes` longblob DEFAULT NULL,

  `UserDefinedREXXLabelMenuName` varchar(80) DEFAULT NULL,

  `AcknowledgeTime` datetime DEFAULT NULL,

  `AcknowledgerZISSourceDescData` blob DEFAULT NULL,

  `AcknowledgerZISSourceOTypNr` int(11) DEFAULT NULL,

  `AcknowledgerZISSourceRBNr` int(11) DEFAULT NULL,

  `DeleteTime` datetime DEFAULT NULL,

  `DeleterZISSourceDescData` blob DEFAULT NULL,

  `DeleterZISSourceOTypNr` int(11) DEFAULT NULL,

  `DeleterZISSourceRBNr` int(11) DEFAULT NULL,

  `EventRawDataType` int(11) DEFAULT NULL,

  `EventRawData` longblob DEFAULT NULL,

  PRIMARY KEY (`UniqueEventUnitID`),

  KEY `NCI_test_P_UserDefID` (`UserDefinedEventUnitID`),

  KEY `NCI_test_P_ModifyTime` (`ModifyTime`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1;