Updated license file https in spine-unity subdir as well.

spine-unity/LICENSE

@@ -6,7 +6,7 @@ Copyright (c) 2013-2025, Esoteric Software LLC
 Integration of the Spine Runtimes into software or otherwise creating
 derivative works of the Spine Runtimes is permitted under the terms and
 conditions of Section 2 of the Spine Editor License Agreement:
-http://esotericsoftware.com/spine-editor-license
+https://esotericsoftware.com/spine-editor-license
 
 Otherwise, it is permitted to integrate the Spine Runtimes into software
 or otherwise create derivative works of the Spine Runtimes (collectively,