fix PHP error: count(): Argument #1 ($value) must be of type Countabl…

…e|array, null given

api/src/Etemplate/Widget/Template.php

@@ -253,7 +253,7 @@ public function run($method_name, $params=array(''), $respect_disabled=false)
 		}
 		//error_log("$this running $method_name() cname: {$this->id} -> expand_name: $expand_name");
 		// Expand if it's different, or it hasn't been expanded yet (no children, and the template actually has children)
-		if($expand_name && ($expand_name != $this->id || count($this->children) == 0 && count(static::$cache[$expand_name]->children) > 0))
+		if($expand_name && ($expand_name != $this->id || count($this->children ?? []) == 0 && count(static::$cache[$expand_name]->children ?? []) > 0))
 		{
 			if (($row_template = self::instance($expand_name)))
 			{