chore: fix default behavior for crossed mode

Author: xmatthias

freqtrade/exchange/exchange.py

@@ -1257,7 +1257,8 @@ def _dry_is_price_crossed(
         is_stop: bool = False,
     ) -> bool:
         if not self.exchange_has("fetchL2OrderBook"):
-            return True
+            # True unless checking a stoploss order
+            return not is_stop
         if not orderbook:
             orderbook = self.fetch_l2_order_book(pair, 1)
         try:

tests/exchange/test_exchange.py

@@ -1173,7 +1173,10 @@ def test__dry_is_price_crossed_without_orderbook_support(default_conf, mocker):
     exchange.fetch_l2_order_book = MagicMock()
     mocker.patch(f"{EXMS}.exchange_has", return_value=False)
     assert exchange._dry_is_price_crossed("LTC/USDT", "buy", 1.0)
+    assert exchange._dry_is_price_crossed("LTC/USDT", "sell", 1.0)
     assert exchange.fetch_l2_order_book.call_count == 0
+    assert not exchange._dry_is_price_crossed("LTC/USDT", "buy", 1.0, is_stop=True)
+    assert not exchange._dry_is_price_crossed("LTC/USDT", "sell", 1.0, is_stop=True)
 
 
 @pytest.mark.parametrize(