tests: fix test-clone on vfat

tests/test-clone.t

@@ -75,7 +75,7 b' No update, with debug option:'
   linking: 8
   linked 8 files
 #else
-  $ hg --debug clone -U . ../c
+  $ hg --debug clone -U . ../c --config progress.debug=true
   linking: 1
   copying: 2
   copying: 3