Get the Hostname

Main library should use ZSH native hostname function

lib/completion.zsh

@@ -39,7 +39,7 @@ hosts=(
   "$_global_ssh_hosts[@]"
   "$_ssh_hosts[@]"
   "$_etc_hosts[@]"
-  `hostname`
+  "$HOST"
   localhost
 )
 zstyle ':completion:*:hosts' hosts $hosts