EDataCal: Remove unused "handle-cancel-operation" signal handler.
EDataCal: Remove unused "handle-cancel-operation" signal handler.

ECalClient never invokes this method, nor does it make sense to.

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