update prezto

.zprezto/modules/utility/init.zsh

@@ -73,7 +73,10 @@ fi
 # ls
 if is-callable 'dircolors'; then
   # GNU Core Utilities
-  alias ls='ls --group-directories-first'
+
+  if zstyle -T ':prezto:module:utility:ls' dirs-first; then
+    alias ls="${aliases[ls]:-ls} --group-directories-first"
+  fi
 
   if zstyle -t ':prezto:module:utility:ls' color; then
     # Call dircolors to define colors if they're missing