Fix algorithm rollover bug wrt keytag conflicts

If there is an algorithm rollover and two keys of different algorithm
share the same keytags, then there is a possibility that if we check
that a key matches a specific state, we are checking against the wrong
key.

Fix this by not only checking for matching key id but also key
algorithm.

(cherry picked from commit f37eb33f29)

lib/dns/keymgr.c

@@ -596,6 +596,7 @@ keymgr_key_match_state(dst_key_t *key, dst_key_t *subject, int type,
 			continue;
 		}
 		if (next_state != NA && i == type &&
+		    dst_key_alg(key) == dst_key_alg(subject) &&
 		    dst_key_id(key) == dst_key_id(subject))
 		{
 			/* Check next state rather than current state. */