[MacPorts] #43733: openslide: use "github.tarball_from releases"

#43733: openslide: use "github.tarball_from releases" --------------------------+------------------------ Reporter: ryandesign@… | Owner: bgilbert@… Type: enhancement | Status: new Priority: Normal | Milestone: Component: ports | Version: 2.2.99 Keywords: haspatch | Port: openslide --------------------------+------------------------ This patch makes openslide use "github.tarball_from releases" (which was just added to the github portgroup) instead of manually setting master_sites. If you have no objections I'd be happy to commit it. -- Ticket URL: <https://trac.macports.org/ticket/43733> MacPorts <http://www.macports.org/> Ports system for OS X