Add workaround for canceling pending build jobs
Add workaround for canceling pending build jobs

As suggested here
https://github.com/appveyor/ci/issues/38#issuecomment-70628826

kasparsd/opensc-latvia-id,nmav/OpenSC,hhonkanen/OpenSC,velter/OpenSC,philipWendland/OpenSC,Jakuje/OpenSC,tidatida/OpenSC,viktorTarasov/OpenSC-SM,velter/OpenSC,rickyepoderi/OpenSC,AktivCo/OpenSC,nmav/OpenSC,fabled/OpenSC,hongquan/OpenSC-main,jpki/OpenSC,LudovicRousseau/OpenSC,velter/OpenSC,martinpaljak/OpenSC,aobaid/OpenSC,germanblanco/OpenSC,jpki/OpenSC,martinpaljak/OpenSC,mouse07410/OpenSC,UIKit0/OpenSC,Jakuje/OpenSC,metsma/OpenSC,mouse07410/OpenSC,frankmorgner/OpenSC,OpenSC/OpenSC,fabled/OpenSC,kasparsd/opensc-latvia-id,CardContact/OpenSC,jpki/OpenSC,CardContact/OpenSC,mtrojnar/OpenSC,metsma/OpenSC,aobaid/OpenSC,rickyepoderi/OpenSC,rickyepoderi/OpenSC,LudovicRousseau/OpenSC,aobaid/OpenSC,hongquan/OpenSC-main,AktivCo/OpenSC,OpenSC/OpenSC,frankmorgner/OpenSC,viktorTarasov/OpenSC-SM,germanblanco/OpenSC,frankmorgner/OpenSC,velter/OpenSC,tidatida/OpenSC,kasparsd/opensc-latvia-id,germanblanco/OpenSC,aobaid/OpenSC,mouse07410/OpenSC,dengert/OpenSC,fabled/OpenSC,AktivCo/OpenSC,dengert/OpenSC,LudovicRousseau/OpenSC,hongquan/OpenSC-main,gemini/OpenSC,fabled/OpenSC,hhonkanen/OpenSC,mtrojnar/OpenSC,Jakuje/OpenSC,OpenSC/OpenSC,gemini/OpenSC,viktorTarasov/OpenSC-SM,tidatida/OpenSC,philipWendland/OpenSC,UIKit0/OpenSC,gemini/OpenSC,UIKit0/OpenSC,martinpaljak/OpenSC,metsma/OpenSC,l1k/OpenSC,nmav/OpenSC,Jakuje/OpenSC,UIKit0/OpenSC,l1k/OpenSC,CardContact/OpenSC,tidatida/OpenSC,frankmorgner/OpenSC,philipWendland/OpenSC,mtrojnar/OpenSC,dengert/OpenSC,l1k/OpenSC,hhonkanen/OpenSC,kasparsd/opensc-latvia-id