cfgupgrade: Fix bug when checking configuration directory

In the condition for checking the configuration directory, one “or” should have
been an “and”. This bug was in cfgupgrade since commit 95e4a814 (June 2008).
Found thanks to a test script.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>