MINOR: quic: Do not accept wrong active_connection_id_limit values

A peer must not send active_connection_id_limit values smaller than 2
which is also the minimum value when not sent.

Make the transport parameters decoding fail in this case.

Must be backported to 2.7.
diff --git a/src/quic_tp.c b/src/quic_tp.c
index ae01361..09921f3 100644
--- a/src/quic_tp.c
+++ b/src/quic_tp.c
@@ -609,6 +609,13 @@
 	    !p->initial_source_connection_id_present)
 		return 0;
 
+	/* Note that if not received by the peer, active_connection_id_limit will
+	 * have QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT as default value. This
+	 * is also the minimum value for this transport parameter.
+	 */
+	if (p->active_connection_id_limit < QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT)
+		return 0;
+
 	return 1;
 }