Drop tractor stream shielding use

piker/data/feed.py

@@ -479,7 +479,6 @@ async def open_feed(
     loglevel: Optional[str] = None,
 
     tick_throttle: Optional[float] = None,  # Hz
-    shielded_stream: bool = False,
 
 ) -> Feed:
     '''
@@ -512,7 +511,7 @@ async def open_feed(
 
         ) as (ctx, (init_msg, first_quote)),
 
-        ctx.open_stream(shield=shielded_stream) as stream,
+        ctx.open_stream() as stream,
 
     ):
         # we can only read from shm

piker/fsp/__init__.py

@@ -180,7 +180,6 @@ async def cascade(
     async with data.feed.maybe_open_feed(
         brokername,
         [symbol],
-        shielded_stream=True,
     ) as (feed, stream):
 
         assert src.token == feed.shm.token