MT#55283 leave SRTP keys in place after DTLS shut

closes #1772

Change-Id: Iaf80e7314730537ca56112cd5f9e1f9c85ca6e3c
(cherry picked from commit afd85a4f94)

daemon/dtls.c

@@ -877,7 +877,6 @@ int dtls(struct stream_fd *sfd, const str *s, const endpoint_t *fsin) {
 
 /* call must be locked */
 void dtls_shutdown(struct packet_stream *ps) {
-
 	if (!ps)
 		return;
 
@@ -906,18 +905,15 @@ void dtls_shutdown(struct packet_stream *ps) {
 		}
 
 		dtls_connection_cleanup(d);
-
-		crypto_reset(&sfd->crypto);
 	}
 
-
 	if (ps->dtls_cert) {
 		X509_free(ps->dtls_cert);
 		ps->dtls_cert = NULL;
 	}
 
 	if (had_dtls)
-		call_stream_crypto_reset(ps);
+		ilogs(crypto, LOG_DEBUG, "Reuse SRTP crypto key");
 }
 
 void dtls_connection_cleanup(struct dtls_connection *c) {