IcingaConfigRenderer(Legacy): Update classes for interface change

refs #12919

library/Director/IcingaConfig/IcingaConfigRendered.php

@@ -26,4 +26,9 @@ class IcingaConfigRendered implements IcingaConfigRenderer
     {
         return $this->toConfigString();
     }
+
+    public function toLegacyConfigString()
+    {
+        return $this->rendered;
+    }
 }

library/Director/Objects/IcingaArguments.php

@@ -393,4 +393,9 @@ class IcingaArguments implements Iterator, Countable, IcingaConfigRenderer
             }
         }
     }
+
+    public function toLegacyConfigString()
+    {
+        return 'UNSUPPORTED';
+    }
 }