feat: make funcprefix a callable option

Author: schuhwerk

src/Context.php

@@ -140,7 +140,7 @@ public static function create($options, $template)
             'safestring' => '\\LightnCandy\\SafeString',
             'safestringalias' => isset($options['safestring']) ? $options['safestring'] : 'LS',
             'rawblock' => false,
-            'funcprefix' => isset($options['funcprefix']) && is_callable($options['funcprefix']) ? $options['funcprefix']( $options, $template ) : uniqid('lcr')
+            'funcprefix' => isset($options['funcprefix']) && is_callable($options['funcprefix']) ? $options['funcprefix']( $options, $template ) : uniqid('lcr'),
         );
 
         $context['ops'] = $context['flags']['echo'] ? array(