Update license header to 2021

common/src/main/java/me/shedaniel/architectury/event/events/client/ClientGuiInputEvent.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of architectury.
- * Copyright (C) 2020 shedaniel
+ * Copyright (C) 2020, 2021 shedaniel
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fabric/src/main/java/me/shedaniel/architectury/mixin/fabric/client/MixinKeyboardHandler.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of architectury.
- * Copyright (C) 2020 shedaniel
+ * Copyright (C) 2020, 2021 shedaniel
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fabric/src/main/java/me/shedaniel/architectury/mixin/fabric/client/MixinMouseHandler.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of architectury.
- * Copyright (C) 2020 shedaniel
+ * Copyright (C) 2020, 2021 shedaniel
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public