Adjust improts to new exception location

tests/strategy/test_strategy.py

@@ -8,7 +8,7 @@ from pathlib import Path
 import pytest
 from pandas import DataFrame
 
-from freqtrade import OperationalException
+from freqtrade.exceptions import OperationalException
 from freqtrade.resolvers import StrategyResolver
 from freqtrade.strategy.interface import IStrategy
 from tests.conftest import log_has, log_has_re