fix bug #821 minify file size is 0

fix for #821 https://github.com/dreamsxin/cphalcon/commit/b33f808a746bde4f3a1858efdf1d63d057fc952d
```php
      * If the collection must not be joined we must print a HTML for each one
      */
     if (Z_TYPE_P(filters) == IS_ARRAY) { 
-      if (!zend_is_true(join)) {
+      if (zend_is_true(join)) {
         if (zend_is_true(local)) {
   
```