Fix usage of maybe unset BASH_VERSION, ZSH_VERSION in strict mode
Fix usage of maybe unset BASH_VERSION, ZSH_VERSION in strict mode

bash: set -u
zsh: set +u

smadhueagle/liquidprompt,dpilone/liquidprompt,nojhan/liquidprompt,alexprengere/liquidprompt,dan-cleinmark/liquidprompt,joshuarubin/dotfiles,joshuarubin/dotfiles,dtschan/liquidprompt,pkkolos/liquidprompt,tsbarnes/liquidprompt,jaesivsm/liquidprompt,milouse/liquidprompt,joshuarubin/dotfiles,BobHood/liquidprompt,joshuarubin/dotfiles,laurentbardin/liquidprompt