Remove interchange multiprocess log hack (#3644)

Prior to PR #3463, the interchange process was launched
with multiprocessing fork and inherited the log configuration
of the parent process.


To give the interchange its own log file, a specific logger,
called "interchange" was used. In PR #2307, this logger was
configured to not propagate entries upwards, so that user
defined root handlers in the parent process do not see
interchange logs.

Since #3463 this special configuration has no longer been
necessary. See #3635 for a related change to signal handlers.

Co-authored-by: Kevin Hunter Kesling <[email protected]>

parsl/executors/high_throughput/interchange.py

@@ -104,7 +104,6 @@ def __init__(self,
         os.makedirs(self.logdir, exist_ok=True)
 
         start_file_logger("{}/interchange.log".format(self.logdir), level=logging_level)
-        logger.propagate = False
         logger.debug("Initializing Interchange process")
 
         self.client_address = client_address