EDataCalView: Unreference the EGdbusCalView in dispose().
EDataCalView: Unreference the EGdbusCalView in dispose().

Recent reference counting fixes uncovered this.  We must have been
leaking EDataCalView references for this to not have been an issue
until now.

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