Removing readonly flag can't be interrupted

[isanae]

When mob tries to delete a directory but gets an access denied error, it assumes files in the directory are read-only. The 7z archive in particular has all files marked as read-only. So op::remove_readonly() will go through all directory recursively and try to chmod every single file. With log level 5 (the default for the log file), this logs a line per file (maybe change the level to dump for this line?)

Since it's in a tight loop in op, it can't be interrupted because the flag actually lives in task. Find a way to propagate this flag to op functions in general. Maybe also set it somewhere in context?