simplify: we don't support MacOS older than 10.12

git-svn-id: https://xpra.org/svn/Xpra/trunk@26856 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/platform/darwin/gui.py

@@ -260,11 +260,7 @@ def get_workareas():
         frame = screen.frame()
         visibleFrame = screen.visibleFrame()
         log(" frame=%s, visibleFrame=%s", frame, visibleFrame)
-        try:
-            #10.7 onwards:
-            log(" backingScaleFactor=%s", screen.backingScaleFactor())
-        except:
-            pass
+        log(" backingScaleFactor=%s", screen.backingScaleFactor())
         x = int(visibleFrame.origin.x - frame.origin.x)
         y = int((frame.size.height - visibleFrame.size.height) - (visibleFrame.origin.y - frame.origin.y))
         w = int(visibleFrame.size.width)