dotsync: test existence of package before install

common/.local/bin/dotsync

@@ -13,7 +13,7 @@ stow_git() {
 multi_stow() {
     ret=0
     for package in common "$(hostname)"; do
-        [ -n "$package" ] && {
+        [ -n "$package" ] && [ -e "${STOW_DIR}/${package}" ] && {
             stow --no-folding -d "$STOW_DIR" -t "$HOME" "$@" "$package"
             ret=$((ret + $?))
         }