Merge branch 'remove-unused-constants' into 'master'

Remove unused constants

See merge request !889

bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementConstants.java

@@ -7,16 +7,6 @@ public interface KeyAgreementConstants {
 	 */
 	byte PROTOCOL_VERSION = 4;
 
-	/**
-	 * The length of the record header in bytes.
-	 */
-	int RECORD_HEADER_LENGTH = 4;
-
-	/**
-	 * The offset of the payload length in the record header, in bytes.
-	 */
-	int RECORD_HEADER_PAYLOAD_LENGTH_OFFSET = 2;
-
 	/**
 	 * The length of the BQP key commitment in bytes.
 	 */