Merge pull request #78 from rexdf/master

sometime compare an empty string will fail with 'unary operator expected'

scripts/select.sh

@@ -43,7 +43,7 @@ do
  continue
  fi
  cer=$(curl https://$ip 2>&1 | grep -Po "'\S*'" |head -1|cut -d \' -f 2)
- if [ $cer != $domain ]
+ if [ "$cer" != $domain ]
  then
  continue
  fi