Make stream draining status logs `.debug()` level

tractor/_root.py

@@ -326,7 +326,7 @@ async def open_root_actor(
                     not entered
                     and not is_multi_cancelled(err)
                 ):
-                    logger.exception("Root actor crashed:")
+                    logger.exception('Root actor crashed:\n')
 
                 # ALWAYS re-raise any error bubbled up from the
                 # runtime!

tractor/_streaming.py

@@ -265,7 +265,7 @@ class MsgStream(trio.abc.Channel):
             try:
                 maybe_final_msg = self.receive_nowait()
                 if maybe_final_msg:
-                    log.cancel(
+                    log.debug(
                         'Drained un-processed stream msg:\n'
                         f'{pformat(maybe_final_msg)}'
                     )