fix(abstract-selectable): add check for is_object before calling `m…

…ethod_exists` on potential integer value

packages/admin/src/Charcoal/Admin/Property/AbstractSelectableInput.php

@@ -109,7 +109,7 @@ protected function parseChoiceVal($value)
             $value = $value->format('Y-m-d-H:i');
         }
 
-        if (method_exists($value, '__toString')) {
+        if (is_object($value) && method_exists($value, '__toString')) {
             $value = strval($value);
         }