moved okex.load_leverage_tiers to new method

freqtrade/exchange/okx.py

@@ -22,7 +22,6 @@ class Okx(Exchange):
         "ohlcv_candle_limit": 300,
         "mark_ohlcv_timeframe": "4h",
         "funding_fee_timeframe": "8h",
-        "can_fetch_multiple_tiers": False,
     }
 
     _supported_trading_mode_margin_pairs: List[Tuple[TradingMode, MarginMode]] = [
@@ -93,31 +92,3 @@ class Okx(Exchange):
 
         pair_tiers = self._leverage_tiers[pair]
         return pair_tiers[-1]['max'] / leverage
-
-    @retrier
-    def load_leverage_tiers(self) -> Dict[str, List[Dict]]:
-        # * This is slow(~45s) on Okex, must make 90-some api calls to load all linear swap markets
-        if self.trading_mode == TradingMode.FUTURES:
-            markets = self.markets
-            symbols = []
-
-            for symbol, market in markets.items():
-                if (self.market_is_future(market)
-                        and market['quote'] == self._config['stake_currency']):
-                    symbols.append(symbol)
-
-            tiers: Dict[str, List[Dict]] = {}
-
-            # Be verbose here, as this delays startup by ~1 minute.
-            logger.info(
-                f"Initializing leverage_tiers for {len(symbols)} markets. "
-                "This will take about a minute.")
-
-            for symbol in sorted(symbols):
-                res = self._api.fetch_leverage_tiers(symbol)
-                tiers[symbol] = res[symbol]
-            logger.info(f"Done initializing {len(symbols)} markets.")
-
-            return tiers
-        else:
-            return {}