Internal errors when "enqueue=True" and "catch=False" should not invalidate the handler

[Delgan]

Let's say some message fail to be logged (due to Exception raised during pickling or by the sink itself). If catch=False, the Exception will be re-raised, but it the user won't be able to catch it because it's raised from a internal thread. The error will be reported on sys.stderr by Python handler, but the thread will die, thus any all the subsequent logging messages will be discarded.

import random
from loguru import logger

def broken_sink(message):
    if random.random() < 0.5:
        raise RuntimeError("Error")
    print(message, end="")

logger.remove()
logger.add(broken_sink, enqueue=True, catch=False, colorize=True)

for i in range(10):
    logger.info(f"Message #{i}")

I think this behavior is not user-friendly and does have much interest. The catch=False makes sense to let user manage exception handling, which is not possible when enqueue=True anyway.

When enqueue=False and catch=False, the caller thread will die, but the sink will remain usable by others threads. The behavior should be the same when enqueue=True.

Also, it could simplify the code.