Updating uasort to be PHP8 compliant

As per ccxt#326  ccxt#326 (comment)

Author: ePascalC

php-binance-api.php

@@ -1424,7 +1424,9 @@ protected function balanceData(array $array, $priceData)
         }
         if (is_array($priceData)) {
             uasort($balances, function ($opA, $opB) {
-                return $opA['btcValue'] < $opB['btcValue'];
+                if ($opA == $opB)
+                    return 0;
+                return ($opA['btcValue'] < $opB['btcValue']) ? -1 : 1;
             });
             $this->btc_value = $btc_value;
             $this->btc_total = $btc_total;