never set the certfp lookup key before verification

irc/accounts.go

 			tx.Set(registeredTimeKey, registeredTimeStr, setOptions)
 			tx.Set(credentialsKey, credStr, setOptions)
 			tx.Set(callbackKey, callbackSpec, setOptions)
-			if certfp != "" {
-				tx.Set(certFPKey, casefoldedAccount, setOptions)
-			}
 			return nil
 		})
 	}()