fix: guard against None request in reject_simple_form_post

queue_batch() calls update_comfyui(None) as an internal trigger when
processing an 'update_comfyui' batch item. update_comfyui() passes this
directly to reject_simple_form_post(), which unconditionally accesses
request.content_type, crashing with:

    AttributeError: 'NoneType' object has no attribute 'content_type'

This broke the 'Update All' button in the legacy Manager UI.

Fix: return None early when request is None. An internal call with no
request object cannot be a cross-origin form POST, so CSRF gating does
not apply.

Fixes #2880

comfyui_manager/common/manager_security.py

@@ -62,6 +62,8 @@ def reject_simple_form_post(request) -> Optional[web.Response]:
         strips parameters), so a ``multipart/form-data; boundary=----X`` header
         is compared as ``multipart/form-data``.
     """
+    if request is None:
+        return None
     if request.content_type in _SIMPLE_FORM_CONTENT_TYPES:
         return web.Response(
             status=400,