net-libs/balde-markdown: fix double KEYWORDS

Double KEYWORDS lines break tools like ekeyword and Nattka.
As per PMS, blank/empty KEYWORDS is implied by not defining
the variable.

See: https://projects.gentoo.org/qa/policy-guide/ebuild-format.html#pg0105
Package-Manager: Portage-3.0.14, Repoman-3.0.2
Signed-off-by: Sam James <sam@gentoo.org>

net-libs/balde-markdown/balde-markdown-0.1.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=5
@@ -15,7 +15,6 @@ SRC_URI="https://github.com/balde/${PN}/releases/download/v${PV}/${P}.tar.bz2"
 KEYWORDS="~amd64 ~x86"
 if [[ ${PV} = *9999* ]]; then
 	SRC_URI=""
-	KEYWORDS=""
 fi
 
 LICENSE="LGPL-2"