Changes

Summary

1. Make cover_image nullable in MessageApplication (commit: 473f67a) (details)

Commit 473f67a2ab38c9e3daa9c087af0f375a7e557fa9 by Florian Spieß Make cover_image nullable in MessageApplication (commit: 473f67a)
	src/main/java/net/dv8tion/jda/core/entities/EntityBuilder.java (diff)
	src/main/java/net/dv8tion/jda/core/entities/MessageActivity.java (diff)