Fix overridability of LP_COLOR_X11_{ON,OFF} from themes
Fix overridability of LP_COLOR_X11_{ON,OFF} from themes

This was broken since LP_COLOR_X11 has been split.
(Commit 452ef223cea64ab8be27b7a273bd18dd4f4bcb36)

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