fix upgrade script

upgrade.zsh

@@ -1,11 +1,11 @@
 #!/usr/bin/env zsh
 
-DOTFILES_PATH="${0:h}"
+DOTFILES_PATH="${0:a:h}"
 cd "$DOTFILES_PATH" || exit 1
+ZSH_DOTFILES="$DOTFILES_PATH/zsh"
 
 git pull --rebase --stat origin master
 git submodule update --init --recursive --remote --progress
 
-DISABLE_AUTO_UPDATE=true
-source "zsh/zgen/zgen.zsh"
-zgen update
+source "$ZSH_DOTFILES/plugins.zsh"
+plugin-upgrade