Saving log_handler to the config file is not currently special-cased,
the value is thus dumped as the repr() of the list, but not deserialized
with literal_eval. This means -s breaks log_handler and the
configuration file example is incorrect (it looks like a list).
Repeated -s further break the log_handler by interpreting the original
value as a string, putting it into a list, then reserialising that with
repr(), injecting a bunch of escaping backslash. The config file is soon
filled with backslashes and doubles in size with each new -s.
Furthermore for some reason the whole thing breaks --log-handler (and
aliases) entirely, once the wrong log_handler has been saved none of
them works anymore.
Fixes#4552Closes#4157