lib/selection*: more precise flags.TCP

I'm overall unsure here, but this does seem as improvement.

lib/rplan.h

@@ -17,7 +17,7 @@ struct kr_qflags {
 	bool NO_MINIMIZE : 1;    /**< Don't minimize QNAME. */
 	bool NO_IPV6 : 1;        /**< Disable IPv6 */
 	bool NO_IPV4 : 1;        /**< Disable IPv4 */
-	bool TCP : 1;            /**< Use TCP for this query. */
+	bool TCP : 1;            /**< Use TCP (or TLS) for this query. */
 	bool RESOLVED : 1;       /**< Query is resolved.  Note that kr_query gets
 				  *   RESOLVED before following a CNAME chain; see .CNAME. */
 	bool AWAIT_IPV4 : 1;     /**< Query is waiting for A address. */

lib/selection_forward.c

@@ -91,7 +91,8 @@ void forward_choose_transport(struct kr_query *qry,
 			(*transport)->protocol = KR_TRANSPORT_UDP;
 		/* We need to propagate this to flags since it's used in other
 		 * parts of the resolver (e.g. logging and stats). */
-		qry->flags.TCP = tcp;
+		qry->flags.TCP = (*transport)->protocol == KR_TRANSPORT_TCP
+			      || (*transport)->protocol == KR_TRANSPORT_TLS;
 	}
 }