Replaced " \t\n\r" with WHITESPACE.

src/server/prot-a-parse.c

@@ -249,7 +249,7 @@ prot_a_get_token(Connection *client)
     old_first = client->first_to_parse;
     
     result = s_strtok(client->unparsed, &client->first_to_parse,
-		      s_fcrea_str(" \t\n\r"));
+		      s_fcrea_str(WHITESPACE));
 
     /* Check that there was at least one trailing blank. */