Add missing backslash continuation in makefile
Add missing backslash continuation in makefile

SPICE/spice,ya-mouse/spice,mathslinux/spice,SPICE/spice,elmarco/spice,elmarco/spice,freedesktop-unofficial-mirror/spice__spice,dezelin/spice,alon/spice-server,mathslinux/spice,virtualAMP/spiceplay,dezelin/spice,freedesktop-unofficial-mirror/spice__spice,dezelin/spice,alon/spice-server,freedesktop-unofficial-mirror/spice__spice,mathslinux/spice,dezelin/spice,ya-mouse/spice,freedesktop-unofficial-mirror/spice__spice,virtualAMP/spiceplay,fgouget/spice,fgouget/spice,ya-mouse/spice,virtualAMP/spiceplay,freedesktop-unofficial-mirror/spice__spice,alon/spice-server,Fantu/spice,alon/spice-server,virtualAMP/spiceplay,Fantu/spice,dezelin/spice,mathslinux/spice,fgouget/spice,Fantu/spice,elmarco/spice,Fantu/spice,SPICE/spice,fgouget/spice,elmarco/spice,mathslinux/spice,alon/spice-server,elmarco/spice