update mysql notification key length, character set and collation (#13414)
update mysql notification key length, character set and collation (#13414)

fixes #13227
balamurugana/minio,vadmeste/minio,donatello/minio,minio/minio,vadmeste/minio,minio/minio,krisis/minio,krisis/minio,donatello/minio,balamurugana/minio