consumer.py: read create_date from original file (instead of temp copy)

In line 328, `self.path` is set to a fresh written copy of the source file. This copy has a different timestamp (=now).

When using the source file's timestamp as `create_date`, it makes much more sense to ask for the timestamp from `self.original_path`

src/documents/consumer.py

@@ -530,7 +530,7 @@ class Consumer(LoggingMixin):
             create_date = date
             self.log.debug(f"Creation date from parse_date: {create_date}")
         else:
-            stats = os.stat(self.path)
+            stats = os.stat(self.original_path)
             create_date = timezone.make_aware(
                 datetime.datetime.fromtimestamp(stats.st_mtime),
             )