Add: Copyright

SchematicSystem_Core/src/de/steamwar/schematicsystem/listener/PlayerEventListener.java

@@ -1,3 +1,22 @@
+/*
+   This file is a part of the SteamWar software.
+
+   Copyright (C) 2022  SteamWar.de-Serverteam
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package de.steamwar.schematicsystem.listener;
 
 import de.steamwar.schematicsystem.commands.SchematicCommandUtils;