fix(module/ssh): Fix error when enable module

USER is replace by 'id -un' to avoid error due to the USER no set

modules/ssh/init.zsh

@@ -25,7 +25,7 @@ if [[ ! -S "$SSH_AUTH_SOCK" ]]; then
   source "$_ssh_agent_env" 2> /dev/null
 
   # Start ssh-agent if not started.
-  if ! ps -U "$USER" -o pid,ucomm | grep -q -- "${SSH_AGENT_PID:--1} ssh-agent"; then
+  if ! ps -U "$(id -un)" -o pid,ucomm | grep -q -- "${SSH_AGENT_PID:--1} ssh-agent"; then
     eval "$(ssh-agent | sed '/^echo /d' | tee "$_ssh_agent_env")"
   fi
 fi