dev-libs/pcc-libs: 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>

dev-libs/pcc-libs/pcc-libs-9999.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2019 Gentoo Authors
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=5
@@ -13,7 +13,6 @@ if [[ ${PV} = 9999 ]]; then
 	ECVS_SERVER="pcc.ludd.ltu.se:/cvsroot"
 	ECVS_MODULE="${PN}"
 	S="${WORKDIR}/${PN}"
-	KEYWORDS=""
 else
 	SRC_URI="ftp://pcc.ludd.ltu.se/pub/pcc-releases/${P}.tgz"
 	KEYWORDS="~amd64 ~x86"