main/openrc: fix hostname script

we should not override hostname set in /etc/conf.d/hostname

fixes #9737

(cherry picked from commit b6b6dcd2)

main/openrc/APKBUILD

@@ -2,7 +2,7 @@
 pkgname=openrc
 pkgver=0.35.5
 _ver=${pkgver/_git*/}
-pkgrel=4
+pkgrel=5
 pkgdesc="OpenRC manages the services, startup and shutdown of a host"
 url="https://gitweb.gentoo.org/proj/openrc.git"
 arch="all"
@@ -89,7 +89,7 @@ d54630d40a2d6b10a325cb012d4efcda997a60c008ca953ce5d60059d3f267308a59dabddf93a5fc
 234c4f3cf39df3350dbea25c00b8d584794b28194f44c726767a6a16d91a26fee1b5d2dd16635f19803fc015b4e9d99c52b23128e6b815938b88365feba8cf59  0007-make-consolefont-service-compatible-with-busyboxs-se.patch
 dbe3f170440f0f357f31ac4d49c56a9a7ec22172df2701bf4a0afdee22aedda1f88b9fa5ffdbe19a5eea3c764ad0e4c802e19b95b7082a72d423d46d30c18edd  0001-fsck-don-t-add-C0-to-busybox-fsck.patch
 12bb6354e808fbf47bbab963de55ee7901738b4a912659982c57ef2777fff9a670e867fcb8ec316a76b151032c92dc89a950d7d1d835ef53f753a8f3b41d2cec  openrc.logrotate
-99b542c0903ad6874b8c308b2e0660a4fe2ff9db962dfec65325cd12c368873a2ae800d5e6d42dc4deff775e1d5c0068869eb72581f7ab16e88d5738afe1d3dd  hostname.initd
+259552165ee5e9ca973bbe18d1d9ec5cc67526cb26a9e0ac717076ef4913bb7ff4055d6ccb9f77996ed9c00b67f46edba552e1a21b836068a112dda2428502b3  hostname.initd
 c06eac7264f6cc6888563feeae5ca745aae538323077903de1b19102e4f16baa34c18b8c27af5dd5423e7670834e2261e9aa55f2b1ec8d8fdc2be105fe894d55  hwdrivers.initd
 b04058ec630e19de0bafefe06198dc1bff8c8d5d2c89e4660dd83dda8bb82a76cdb1d8661cce88e4a406aa6b4152e17efff52d3eb18ffaec0751d0b6cdbcc48a  modules.initd
 27c036a2c07f658f7fb1e066c59dc494674ba0d81bcb85fea9caffec28ee537eb11e863e20aa4b1c88607f12496ac66d5b092c787c86ff8b8a80e423a8d99440  modloop.initd

main/openrc/hostname.initd

@@ -10,7 +10,7 @@ start() {
 	if [ -s /etc/hostname ] ; then
 		opts="-F /etc/hostname"
 	else
-		opts="localhost"
+		opts="${hostname:-localhost}"
 	fi
 	ebegin "Setting hostname"
 	hostname $opts