Fix e-data-book-factory.c regression.
Fix e-data-book-factory.c regression.

Distrotech/evolution-data-server,matzipan/evolution-data-server,gcampax/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,gcampax/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server,gcampax/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,gcampax/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server