Changes

Summary

1. avoid duplicate mails in sendall when using flatfile backend (commit: 3e8d4fa) (details)

Commit 3e8d4fa19e67f00d8c762c05b82f5ead24c5db71 by Flo.e3 avoid duplicate mails in sendall when using flatfile backend (commit: 3e8d4fa)
	src/main/java/codecrafter47/bungeemail/FlatFileBackend.java (diff)
	src/main/java/codecrafter47/bungeemail/MySQLBackend.java (diff)