update spec to reflect the downgraded loglevel for naming complaints.

svn:r6388

doc/dir-spec.txt

@@ -591,7 +591,7 @@ $Id$
    consecutive times) a network-status for every authority, and at
    least one of the authorities is "Naming", and no live "Naming"
    authorities publish a binding for the router's nickname, the
-   router SHOULD remind the operator that the chosen nickname is not
+   router MAY remind the operator that the chosen nickname is not
    bound to this key at the authorities, and suggest contacting the
    authority operators.