community/py3-mistune: drop maintainership

I haven't had any interest in maintaining this for a while, let's
actually reflect that.

community/py3-mistune/APKBUILD

 # Contributor: Newbyte <newbie13xd@gmail.com>
-# Maintainer: Newbyte <newbie13xd@gmail.com>
+# Maintainer:
 pkgname=py3-mistune
 pkgver=3.0.2
-pkgrel=1
+pkgrel=2
 pkgdesc="Python Markdown parser module"
 url="https://github.com/lepture/mistune"
 arch="noarch"