Allow updating media file even if path is disallowed (fixes #653)

Author: DavidMStraub

gramps_webapi/api/file.py

@@ -185,8 +185,8 @@ def get_file_size(self) -> int:
         """
         try:
             self._check_path()
-        except ValueError:
-            abort_with_message(403, "File access not allowed")
+        except ValueError as exc:
+            raise FileNotFoundError from exc
         return os.path.getsize(self.path_abs)
 
     def send_file(