Do not ignore @Index when checking for free-floating node

This is currently being discussed at json-ld/json-ld.org#300

Processor.php

@@ -472,14 +472,9 @@ public function expand(&$element, $activectx = array(), $activeprty = null, $fra
         }
 
         // All properties have been processed. Make sure the result is valid
-        // and optimize object where possible
+        // and optimize it where possible
         $numProps = count(get_object_vars($element));
 
-        // Indexes are allowed everywhere
-        if (property_exists($element, '@index')) {
-            $numProps--;
-        }
-
         // Remove free-floating nodes
         if ((false === $frame) && ((null === $activeprty) || ('@graph' === $activeprty)) &&
             (((0 === $numProps) || property_exists($element, '@value') || property_exists($element, '@list') ||
@@ -489,6 +484,11 @@ public function expand(&$element, $activectx = array(), $activeprty = null, $fra
             return;
         }
 
+        // Indexes are allowed everywhere
+        if (property_exists($element, '@index')) {
+            $numProps--;
+        }
+
         if (property_exists($element, '@value')) {
             $numProps--;  // @value
             if (property_exists($element, '@language')) {