Update SerializerUtils.java

Author: Paultagoras

client-v2/src/main/java/com/clickhouse/client/api/data_formats/internal/SerializerUtils.java

@@ -741,8 +741,6 @@ public static BigDecimal convertToBigDecimal(Object value) {
             return (BigDecimal) value;
         } else if (value instanceof BigInteger) {
             return new BigDecimal((BigInteger) value);
-        } else if (value instanceof BigDecimal) {
-            return (BigDecimal) value;
         } else if (value instanceof Number) {
             return BigDecimal.valueOf(((Number) value).doubleValue());
         } else if (value instanceof String) {