main/postmarketos-base: depend on the keys package (MR 2477)

Have the keys be packagemanaged by default instead of preloading it
once with pmbootstrap

main/postmarketos-base/APKBUILD

 pkgname=postmarketos-base
-pkgver=14
+pkgver=15
 pkgrel=0
 pkgdesc="Meta package for minimal postmarketOS base"
 url="https://postmarketos.org"
@@ -11,6 +11,7 @@ depends="
 	openssh
 	postmarketos-mkinitfs
 	postmarketos-mvcfg
+	postmarketos-keys
 	sudo
 	"
 install="$pkgname.post-install $pkgname.pre-upgrade $pkgname.post-upgrade"