Detect Debian 9.X as stretch too
Detect Debian 9.X as stretch too

GStreamer/cerbero,nirbheek/cerbero,EricssonResearch/cerbero,flexVDI/cerbero,centricular/cerbero,fluendo/cerbero,EricssonResearch/cerbero,flexVDI/cerbero,nirbheek/cerbero,justinjoy/cerbero,OptoFidelity/cerbero,fluendo/cerbero,GStreamer/cerbero,atsushieno/cerbero,atsushieno/cerbero,nirbheek/cerbero,GStreamer/cerbero,justinjoy/cerbero,flexVDI/cerbero,justinjoy/cerbero,OptoFidelity/cerbero,EricssonResearch/cerbero,nirbheek/cerbero,fluendo/cerbero,atsushieno/cerbero,GStreamer/cerbero,centricular/cerbero,centricular/cerbero,centricular/cerbero,GStreamer/cerbero,atsushieno/cerbero,centricular/cerbero,flexVDI/cerbero,OptoFidelity/cerbero,fluendo/cerbero,atsushieno/cerbero,justinjoy/cerbero,fluendo/cerbero,EricssonResearch/cerbero,flexVDI/cerbero,EricssonResearch/cerbero,OptoFidelity/cerbero