Misc entry has Year and Month both in Optional and Deprecated tabs

[homocomputeris]

JabRef 4.3.1
Linux 4.18.14-arch1-1-arch amd64
Java 1.8.0_192

Steps to reproduce:

1. Create and select a Misc entry in biblatex mode

While these fields should be in the Required tab, as BibLaTeX manual says:

Required fields: author/editor, title, year/date
Optional fields: subtitle, titleaddon, language,howpublished,type,version,note,organization,location,date,month,year,addendum,pubstate,di,eprint,eprintclass,eprinttype,url,urldate

[Siedlerchr]

I talked to the biblatex guys plk/biblatex#833 and it's an error in the specification. It does not make sense to add the fields double. Year and months are only valid in required fields