epm-repofix: fix static apt-repo require

bin/epm-repofix

@@ -60,7 +60,7 @@ __replace_alt_version_in_repo()
 	local i
 	assure_exists apt-repo
 	#echo "Upgrading $DISTRNAME from $1 to $2 ..."
-	apt-repo list | sed -e "s|\($1\)|{\1}->{$2}|g" | grep -E --color -- "$1"
+	a='' apt-repo list | sed -e "s|\($1\)|{\1}->{$2}|g" | grep -E --color -- "$1"
 	# ask and replace only we will have changes
 	if a='' apt-repo list | grep -E -q -- "$1" ; then
 		__replace_text_in_alt_repo "/^ *#/! s!$1!$2!g"