dbus-python: fix mirroring

Clear distfiles instead of overriding a lot of other stuff.

devel/dbus-python/Portfile

@@ -23,10 +23,7 @@ homepage        https://www.freedesktop.org/wiki/Software/dbus/
 
 if {${name} eq ${subport}} {
     # set up dbus-python as a stub port that depends on the default dbus-pythonXY
-    master_sites {}
-    fetch {}
-    checksum {}
-    extract {}
+    distfiles
     supported_archs noarch
 
     depends_lib port:${name}${python_default_version}