add copyright headers

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd_client/AddressBook.cpp

@@ -1,3 +1,11 @@
+/*
+* Copyright (c) 2013-2020, The PurpleI2P Project
+*
+* This file is part of Purple i2pd project and licensed under BSD3
+*
+* See full license text in LICENSE file at top of project tree
+*/
+
 #include <string.h>
 #include <inttypes.h>
 #include <string>