Initialize variable pKeyDup in multiSelectOrderBy(). Technically it doesn't need to be initialized, but the reasoning required to come to that conclusion is too complicated for some automated systems. So it is initialized to keep some compilers happy. Ticket #3382. (CVS 5710)

FossilOrigin-Name: bd58be6ecf0a22f3c8404bd7094ab5e13e19b1c4