When converting an aggregate expression to AGG_COLUMN, be sure to remove

the EP_Unlikely flag if it is present.
[forum:/info/fbfe330a2009d036|Forum post fbfe330a2009d036].

FossilOrigin-Name: 48e65f18b2ebbe786e84e208f2c6c68de6067ba86912fea5a120fd41d0af2184