Merge branch 'rootbld-repo-file' into 'master'

abuild-rootbld: Attempt to improve creation of /etc/apk/repositories

See merge request alpine/abuild!198

abuild.in

@@ -2592,8 +2592,11 @@ rootbld() {
 
 		envsubst | while read -r repository; do
 			echo "$repository"
-			echo "$REPODEST/${repository##*/}"
+			if [ -d "$REPODEST/${repository##*/}" ]; then
+				echo "$REPODEST/${repository##*/}"
+			fi
 		done
+		echo "$REPODEST/$repo"
 	) < "$repo_template" > "$BUILD_ROOT/etc/apk/repositories"
 
 	calcdeps