graphviz: fix distfile
graphviz: fix distfile

The URL currently does not contain the version number. This needs to
be verified carefully on the next update.

coredumb/void-packages,necrophcodr/void-packages,NeoChontrix/void-packages,necrophcodr/void-packages,floGik/void-packages,floGik/void-packages,coredumb/void-packages,coredumb/void-packages,necrophcodr/void-packages,floGik/void-packages,coredumb/void-packages,necrophcodr/void-packages,NeoChontrix/void-packages,NeoChontrix/void-packages,NeoChontrix/void-packages,NeoChontrix/void-packages,floGik/void-packages,floGik/void-packages,coredumb/void-packages,floGik/void-packages,necrophcodr/void-packages,coredumb/void-packages,NeoChontrix/void-packages