tests (e2e/CLI/set_get): fix RSM request:

items are stored in chronological order in Pubsub, and as we want the more recent one, we
need to set `before=''`. Otherwise, we can get a wrong item from a previous test.

tests/e2e/libervia-cli/test_libervia-cli.py

@@ -189,7 +189,7 @@ class TestLiberviaCliBlog:
 
     def test_set_get(self, li_json):
         li.blog.set(_in="markdown **bold** [link](https://example.net)")
-        item_data = li_json.blog.get(max=1)
+        item_data = li_json.blog.get(max=1, before="")
         item = item_data[0][0]
         metadata = item_data[1]
         assert metadata['service'] == "account1@server1.test"