Fix random test failure

freqtrade/optimize/backtesting.py

@@ -130,6 +130,9 @@ class Backtesting:
         self.abort = False
 
     def __del__(self):
+        self.cleanup()
+
+    def cleanup(self):
         LoggingMixin.show_output = True
         PairLocks.use_db = True
         Trade.use_db = True

tests/optimize/test_backtesting.py

@@ -535,6 +535,8 @@ def test_backtest__enter_trade(default_conf, fee, mocker) -> None:
     trade = backtesting._enter_trade(pair, row=row)
     assert trade is None
 
+    backtesting.cleanup()
+
 
 def test_backtest_one(default_conf, fee, mocker, testdatadir) -> None:
     default_conf['use_sell_signal'] = False