fix nested set issue in php7 (see https://3v4l.org/IARp7)

Author: kbond

lib/Gedmo/Tree/Strategy/ORM/Nested.php

@@ -533,6 +533,9 @@ public function shiftRL(EntityManager $em, $class, $first, $delta, $root = null)
                 if ($node instanceof Proxy && !$node->__isInitialized__) {
                     continue;
                 }
+                if (get_class($node) !== $class) {
+                    continue;
+                }
                 $oid = spl_object_hash($node);
                 $left = $meta->getReflectionProperty($config['left'])->getValue($node);
                 $currentRoot = isset($config['root']) ? $meta->getReflectionProperty($config['root'])->getValue($node) : null;
@@ -599,6 +602,9 @@ public function shiftRangeRL(EntityManager $em, $class, $first, $last, $delta, $
                 if ($node instanceof Proxy && !$node->__isInitialized__) {
                     continue;
                 }
+                if (get_class($node) !== $class) {
+                    continue;
+                }
                 $left = $meta->getReflectionProperty($config['left'])->getValue($node);
                 $right = $meta->getReflectionProperty($config['right'])->getValue($node);
                 $currentRoot = isset($config['root']) ? $meta->getReflectionProperty($config['root'])->getValue($node) : null;