Fix minor typo in comment in Configure

Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5825)

Configure

@@ -423,7 +423,7 @@ my %deprecated_disablables = (
     "ui" => "ui-console",
     );
 
-# All of the following is disabled by default (RC5 was enabled before 0.9.8):
+# All of the following are disabled by default:
 
 our %disabled = ( # "what"         => "comment"
                   "asan"		=> "default",