Fixed data-type in Smarty exception calss

libraries/Smarty/libs/sysplugins/smartycompilerexception.php

@@ -20,7 +20,7 @@ class SmartyCompilerException extends SmartyException
      *
      * @type int|null
      */
-    public $line = null;
+    public int $line = 0;
 
     /**
      * The template source snippet relating to the error