Fix: Fixed typo in file header.

MMakefile

 #-------------------------------------------------------------------------------
 # MASTER MAKEFILE FOR MENTAT-NG PROJECT
 #
-# Copyright (c) since 2016, CESNET, z. s. p. o.
+# Copyright (C) since 2016, CESNET, z. s. p. o.
 # Author: Jan Mach <jan.mach@cesnet.cz>
 # Use of this source is governed by an MIT license, see LICENSE file.
 #-------------------------------------------------------------------------------