The configuration entered is not valid. A database connection could not be established. Please check your configuration and try again.
	com.atlassian.stash.internal.db.DefaultDatabaseManager.validateConfiguration(DefaultDatabaseManager.java:230)
	com.atlassian.stash.internal.db.DefaultDatabaseManager.prepareDatabase(DefaultDatabaseManager.java:187)
	com.atlassian.stash.internal.maintenance.SpringMaintenanceTaskFactory.setupTask(SpringMaintenanceTaskFactory.java:159)
	...
Could not get JDBC Connection; nested exception is java.sql.SQLException: Unknown system variable 'storage_engine'
	org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)
	com.atlassian.stash.internal.db.DefaultDatabaseValidator.validate(DefaultDatabaseValidator.java:44)
	com.atlassian.stash.internal.db.DefaultDatabaseManager.validateConfiguration(DefaultDatabaseManager.java:227)
	...
Unknown system variable 'storage_engine'
	com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
	com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
	com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
	...