Fix TestExtractor tests when running on MySQL

Nuxeo-Work-apidoc-xml-extractor-2:test:d297eeaf-e8bf-4eda-873e-601b57fe325d:xml:extractor 05:39:57,548 ERROR [SessionImpl] Exception during transaction commit
org.nuxeo.ecm.core.api.NuxeoException: Could not insert: INSERT INTO `apidoccommon` (`id`, `attributes`) VALUES (?, ?)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCRowMapper.insertSimpleRows(JDBCRowMapper.java:581)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCRowMapper.writeCreates(JDBCRowMapper.java:483)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCRowMapper.write(JDBCRowMapper.java:452)
	at sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapperConnector.doInvoke(JDBCMapperConnector.java:42)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapperConnector.invoke(JDBCMapperConnector.java:85)
	at com.sun.proxy.$Proxy70.write(Unknown Source)
	at org.nuxeo.ecm.core.storage.sql.SoftRefCachingRowMapper.write(SoftRefCachingRowMapper.java:359)
	at org.nuxeo.ecm.core.storage.sql.SessionImpl.doFlush(SessionImpl.java:360)
	at org.nuxeo.ecm.core.storage.sql.SessionImpl.flush(SessionImpl.java:333)
	at org.nuxeo.ecm.core.storage.sql.SessionImpl.end(SessionImpl.java:1398)
	at org.apache.geronimo.transaction.manager.WrapperNamedXAResource.end(WrapperNamedXAResource.java:61)
	at org.apache.geronimo.transaction.manager.TransactionImpl.endResources(TransactionImpl.java:569)
	at org.apache.geronimo.transaction.manager.TransactionImpl.endResources(TransactionImpl.java:548)
	at org.apache.geronimo.transaction.manager.TransactionImpl.beforePrepare(TransactionImpl.java:408)
	at org.apache.geronimo.transaction.manager.TransactionImpl.commit(TransactionImpl.java:255)
	at org.apache.geronimo.transaction.manager.TransactionManagerImpl.commit(TransactionManagerImpl.java:252)
	at org.nuxeo.runtime.jtajca.NuxeoContainer$UserTransactionImpl.commit(NuxeoContainer.java:546)
	at org.nuxeo.runtime.transaction.TransactionHelper.commitOrRollbackTransaction(TransactionHelper.java:334)
	at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransaction(AbstractWork.java:440)
	at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransactionAndCheckExceptions(AbstractWork.java:377)
	at org.nuxeo.ecm.core.work.AbstractWork.run(AbstractWork.java:338)
	at org.nuxeo.ecm.core.work.WorkHolder.run(WorkHolder.java:57)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.sql.BatchUpdateException: Data truncation: Data too long for column 'attributes' at row 1
	at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2028)
	at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1451)
	at org.tranql.connector.jdbc.StatementHandle.executeBatch(StatementHandle.java:155)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCRowMapper.insertSimpleRows(JDBCRowMapper.java:566)
	... 27 more
Caused by: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column 'attributes' at row 1
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3607)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3541)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
	at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2427)
	at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1980)
	... 30 more