Remove useSelect2 from the defaultProps

bin/defaultProps.json

@@ -120,9 +120,6 @@
 	// lines of these sheets will receive has-ref or no-ref html classes
 	"cdb.indicateRefs": [],
 
-	// will be removed once confidence in the new dropdown has grown
-	"cdb.useSelect2": false,
-
 	// It's possible to separately control CDB configurations per sheet and column with following keys:
 	// "cdb.mySheetName": { /* Applies to all File columns in sheet with mySheetName */ }
 	// "cdb.mySheetName.myColumnName": { /* Applies only to File column with name myColumnName, located in mySheetName */ }