Fixes redundant tag sending and updates the test to be correct with the new behavior

Author: SiverJohn

btrdb/stream.py

@@ -823,7 +823,7 @@ def _update_tags_collection(self, tags, collection):
         """
         :meta private:
         """
-        tags = self.tags() if tags is None else tags
+        tags = {} if tags is None else tags
         collection = self.collection if collection is None else collection
         if collection is None:
             raise BTRDBValueError(

tests/btrdb/test_stream.py

@@ -278,7 +278,7 @@ def test_update_collection(self):
 
         stream.update(collection=collection)
         stream._btrdb.ep.setStreamTags.assert_called_once_with(
-            uu=uu, expected=42, tags=stream.tags(), collection=collection
+            uu=uu, expected=None, tags={}, collection=collection
         )
         stream._btrdb.ep.setStreamAnnotations.assert_not_called()