minor fix in creating a stream NACK for rdb and defrag tests

tests/integration/rdb.tcl

@@ -48,7 +48,7 @@ start_server [list overrides [list "dir" $server_path]] {
                 r xadd stream * bar $j
             }
         }
-        r xgroup create stream mygroup $
+        r xgroup create stream mygroup 0
         r xreadgroup GROUP mygroup Alice COUNT 1 STREAMS stream >
         set digest [r debug digest]
         r debug reload

tests/unit/memefficiency.tcl

@@ -104,7 +104,7 @@ start_server {tags {"defrag"}} {
             r sadd set a b c d
             r xadd stream * item 1 value a
             r xadd stream * item 2 value b
-            r xgroup create stream mygroup $
+            r xgroup create stream mygroup 0
             r xreadgroup GROUP mygroup Alice COUNT 1 STREAMS stream >
 
             # create big keys with 10k items