[setup] Fix ubuntu glob

setup_ubuntu.sh

@@ -5,6 +5,8 @@
 #
 # Distributed under terms of the MIT license.
 #
+shopt -s nullglob
+
 sudo apt -y update
 sudo apt -y dist-upgrade
 sudo apt -y install neovim zsh tmux virtualenvwrapper powerline fonts-powerline python3 python3-pip python3-pynvim