Fix console blanking (#676)

So I was wrong.. /etc/issue needs to contain the escape sequence output
by setterm,  not the actual call to setterm itself. My previous testing
of this was faulty, which led me to believe the previous implementation
of this would work.

main/postmarketos-base/APKBUILD

@@ -1,6 +1,6 @@
 pkgname=postmarketos-base
 pkgver=3
-pkgrel=6
+pkgrel=7
 pkgdesc="Meta package for minimal postmarketOS base"
 url="https://github.com/postmarketOS"
 arch="noarch"
@@ -55,4 +55,4 @@ sha512sums="c6de3b44bc45b9f9c641a7e34c69a481ee39b99ac0251cd28f2b3aae49c1a8d1ca44
 3ceeee37f558e7c95ad973692b6a437f997e6b46c3d1c2257ddfb1529a5633477373aa123c7f08164e818daae50acb203d151379f27ca11bd458809e6a0d4de7  swapfile
 f5cc0f1265955d2646e5f099dd4b5d4c287945bfc18c16044db57670d456f55c678fc11cc59e6dab3fa340832ce869d516302a3a35c13518539ed0cedca51819  swapfile.init
 e0d2d48b82a03239a4c0a00acaf83e00d397c23a8d7c71053d4e2a383357c22dcedef9e81b0e12a1d7514e1fdbe0bb3eb82613d18b29034a7ce5447f13c84a53  swapfile.conf
-90a4ced45eded690a5ee3ef65991827d2bbc0f8ba964fbafb1ff703a0deebf61d48b335d942ce9175d57e4ec18ff1f4820ce5c04255d5b97dad7d8fb72264d48  postmarketos-base.post-install"
+7b364339d6de29aabdc25e667f346fc1f9db0e8ec32f40f8e7895616aa5843ac46fdf7c52355f1540648928479017b44abae023d1b217ab586b0b16be264d731  postmarketos-base.post-install"

main/postmarketos-base/postmarketos-base.post-install

@@ -44,7 +44,8 @@ write_unless_modified() {
   {
 	echo 'Welcome to postmarketOS'
 	echo 'Kernel \r on an \m (\l)'
-	echo 'setterm -blank 5 -powersave on'
+	# setterm -powersave on -blank 5
+	echo -ne "\033[9;5]"
   } | write_unless_modified /etc/issue
 # Set /etc/motd
 {