Clarify the licensing terms

As per the contract, Vasek's contributions are owned by FIT CVUT. CESNET
of course owns my stuff, and the result is available under the terms of
Apache 2.

Change-Id: I868f87496158597df65f6086fbacdf3c60295efd
diff --git a/src/main.cpp b/src/main.cpp
index e94ede8..3742e47 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
+ * Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
  *
  * Written by Jan Kundrát <jan.kundrat@cesnet.cz>
  *