test: improve test resiliance

Author: xmatthias

tests/rpc/test_rpc.py

@@ -992,6 +992,7 @@ def test_performance_handle(default_conf_usdt, ticker, fee, mocker) -> None:
     assert len(res) == 3
     assert res[0]["pair"] == "NEO/USDT"
     assert res[0]["count"] == 1
+    assert res[0]["profit_abs"] == 3.9875
     assert res[0]["profit_pct"] == 5.0