fix(wtf): quote array assignment

Author: akinomyoga

completions/wtf

@@ -9,7 +9,7 @@ _comp_cmd_wtf()
     [[ $prev == -f ]] && _comp_compgen_filedir && return
     [[ ${words[*]} == *\ -f* ]] && addf= || addf=-f
     if [[ $cur == -* ]]; then
-        COMPREPLY=($addf)
+        COMPREPLY=(${addf:+"$addf"})
         return
     fi