Revert "Add 'dict' support to serializer."
Revert "Add 'dict' support to serializer."

This reverts commit a4abdabf71451e03ea4a5f7b7ba3661cca129892.

Distrotech/urlgrabber,henrysher/urlgrabber,Distrotech/urlgrabber,oe-lite/urlgrabber,tradej/urlgrabber,henrysher/urlgrabber,Distrotech/urlgrabber,Distrotech/urlgrabber,henrysher/urlgrabber,tradej/urlgrabber,tradej/urlgrabber,henrysher/urlgrabber,oe-lite/urlgrabber,oe-lite/urlgrabber,oe-lite/urlgrabber