Merge pull request #131 from rummik/patch-1

Fix parse error in Zsh 4.3.17

nvm.sh

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