databases/cego: update 2.49.16 -> 2.49.20

• Removed lockPool call in CegoAdminThread::srvExportTableSet and srvExportTable to avoid lock timeouts during long running exports
• Made some code cleanup in CegoAdminThread ( exception consolidation )
• db thread query history information, added timestamp and cost information
• Introduces new cgadm admin commands o queryhist last n o queryhist cost n to show the query history for all db threads in the db thread pool. The last n queries or the most expensive n queries are indicated
• Added query history suppport for cgadm screen mode
• CegoAdmScreen to fully support of query history feature ( last and full over all db threads ).
• Screen2:Grid schema patches added to satisfy new column alignment feature for Screen2
• Fix added in CegoDBThreadPool. CegoAdminThreadPool and CegoLogThreadPool. If database hostname is not defined, the corresponding service is served on any hostname. This avoids confusion regarding IPv4 and IPv6 host configuration ( e.g. on MacOSX Sequoia, java seems to handle localhost always as IPv4 127.0.0.1, while on POSIX layer, it is mapped to ::1, a bit strange )
• Added new lfcbase Net::serve6 method to db, admin and log threadpool. If no hostname is defined in database xml, an IP dual stack configuration is set up.