_autoenv_source: grep for unstash also

Just for consistency.

autoenv.zsh

@@ -290,7 +290,7 @@ _autoenv_source() {
   # XXX: pollutes environment with e.g. `stash`, and `autostash` will cause
   # an overwritten `stash` function to be called!
   if ! (( $+functions[autostash] )); then
-    if \grep -qE '\b(autostash|autounstash|stash)\b' $autoenv_env_file; then
+    if \grep -qE '\b(autostash|autounstash|stash|unstash)\b' $autoenv_env_file; then
       source ${${funcsourcetrace[1]%:*}:h}/lib/varstash
     fi
     # NOTE: Varstash uses $PWD as default for varstash_dir, we might set it to