gnome3.updateScript: improve pre-release detection

Previously all versions with minor >= 90 were considered pre-release,
which failed to consider versions like 0.100.

Let’s limit the range to 90–99 and 900–999.

pkgs/desktops/gnome-3/find-latest-version.py

@@ -12,7 +12,7 @@ def odd_unstable(version_str, selected):
         return True
 
     even = version[1] % 2 == 0
-    prerelease = version[1] >= 90
+    prerelease = (version[1] >= 90 and version[1] < 100) or (version[1] >= 900 and version[1] < 1000)
     stable = even and not prerelease
     if selected == 'stable':
         return stable