Fix warning when unsetopt isn't found

nvm.sh

@@ -12,7 +12,7 @@ fi
 
 # Make zsh glob matching behave same as bash
 # This fixes the "zsh: no matches found" errors
-if [ ! -z "$(which unsetopt)" ]; then
+if [ ! -z "$(which unsetopt 2>/dev/null)" ]; then
     unsetopt nomatch 2>/dev/null
 fi