main/protobuf: install vim files with install_if

main/protobuf/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=protobuf
 pkgver=2.6.1
-pkgrel=3
+pkgrel=4
 pkgdesc="Library for extensible, efficient structure packing"
 url="http://code.google.com/p/protobuf/"
 arch="all"
@@ -54,6 +54,7 @@ py() {
 vim() {
 	depends=""
 	pkgdesc="Vim syntax for $pkgname"
+	install_if="$pkgname=$pkgver-r$pkgrel vim"
 	arch="noarch"
 
 	install -Dm644 "$_builddir"/editors/proto.vim \