Fix for PHP 7.2

diff -ru old/Callback.php src/Callback.php
--- src/Callback.php	2017-11-09 10:29:37.999024003 +0100
+++ src/Callback.php	2017-11-09 10:39:51.600295131 +0100
@@ -13,8 +13,11 @@
 /**
  * @deprecated
  */
-class Callback extends Object
+class Callback
 {
+    use \Nette\SmartObject;
+
+
 	/** @var callable */
 	private $cb;
 
diff -ru old/Templating/Template.php src/Templating/Template.php
--- src/Templating/Template.php	2017-11-09 10:29:38.000024009 +0100
+++ src/Templating/Template.php	2017-11-09 10:39:13.758095759 +0100
@@ -16,8 +16,12 @@
 /**
  * @deprecated
  */
-class Template extends Nette\Object implements ITemplate
+class Template implements ITemplate
 {
+    use \Nette\SmartObject { 
+        \Nette\SmartObject::__call as __parent_call;
+    }
+
 	/** @var array of function (Template $sender); Occurs before a template is compiled - implement to customize the filters */
 	public $onPrepareFilters = array();
 
@@ -311,7 +315,7 @@
 					return Callback::invokeArgs($this->helpers[$lname], $args);
 				}
 			}
-			return parent::__call($name, $args);
+			return $this->__parent_call($name, $args);
 		}
 
 		return Callback::invokeArgs($this->helpers[$lname], $args);