Fix usage of good old objects with VMT.

symdef.pas, tobjectdef:
  * vmtmethodoffset: the "else" part of the case is intended for odt_object, so revert to "2" instead of "3"


git-svn-id: http://svn.freepascal.org/svn/fpc/branches/svenbarth@28913 3ad0048d-3df7-0310-abae-a5850022a9f2