bird: run with restricted privileges

srcpkgs/bird/files/bird/run

@@ -1,2 +1,2 @@
 #!/bin/sh
-exec bird -f ${OPTS:=-c /etc/bird.conf}
+exec bird -f -u _bird -g _bird ${OPTS:=-c /etc/bird.conf}

srcpkgs/bird/template

@@ -1,7 +1,7 @@
 # Template file for 'bird'
 pkgname=bird
 version=2.0.2
-revision=1
+revision=2
 build_style=gnu-configure
 conf_files="/etc/bird.conf"
 hostmakedepends="flex autoconf"
@@ -13,6 +13,8 @@ homepage="https://bird.network.cz"
 distfiles="ftp://bird.network.cz/pub/bird/bird-${version}.tar.gz"
 checksum=035f91d6f568f8ed438a0814235ac4c5c79147cd2acf201322c307732883480f
 
+system_accounts="_bird"
+
 post_install() {
 	vsv bird
 }