databases/cego: update 2.38.10 -> 2.38.12

• Small optimization in CegoAttrCond::checkIndex, removed primary flag, since this is done now by attribute ordering. This leads to full index trace match instead of trace with index support and so, additional unnecessary predicate evaluation is avoided.
• More rework for btree evaluation in CegoBTreeCursor
• Optimization in CegoBTreeCursor::getNext. Instead of calling getNext in a recursive way, this is now done in a iterative way. This might avoid heavy stacking in case of special query constraints ( e..g multi dimensional btrees and range conditions like a > 400 and b betweeen 'AAA' and 'DDD' )

Submitted by: Bjoern Lemke <lemke@lemke-it.com>