Improve phrasing

wiki/src/doc/about/openpgp_keys/signing_key_revocation.mdwn

@@ -209,7 +209,8 @@ plausible.
 
 Keep in mind that we could still revoke the signing key ourselves as
 long as three of us are able to communicate and gather their shares. So
-we only need your help if only two of us are still able to communicate.
+we only need your help if no more than two of us are still able to
+communicate.
 
 Unless you really want to start the key revocation process, do not write
 to this mailing list.