Avoid 'title:parse error' with single quotes in $CMD

Fixes #2182

lib/termsupport.zsh

@@ -28,7 +28,7 @@ function omz_termsupport_preexec {
   setopt extended_glob
   local CMD=${1[(wr)^(*=*|sudo|ssh|rake|-*)]} #cmd name only, or if this is sudo or ssh, the next cmd
   local LINE="${2:gs/%/%%}"
-  title "$CMD" '%100>...>$LINE%<<'
+  title '$CMD' '%100>...>$LINE%<<'
 }
 
 autoload -U add-zsh-hook