RELICENSE: Aleksander Melnikov

Grant received via Github PR comment:

https://github.com/zeromq/libzmq/pull/1413#issuecomment-520233278

RELICENSE/malexzx.md

+# Permission to Relicense under MPLv2
+
+This is a statement by Aleksander Melnikov
+that grants permission to relicense its copyrights in the libzmq C++
+library (ZeroMQ) under the Mozilla Public License v2 (MPLv2).
+
+A portion of the commits made by the Github handle "malexzx", with
+commit author "Aleksander Melnikov", are copyright of Aleksander Melnikov.
+This document hereby grants the libzmq project team to relicense libzmq,
+including all past, present and future contributions of the author listed above.
+
+Aleksander Melnikov
+2019/08/11