How to send more than 20bytes in each transaction with bleSerial.write()?

[pvonmoradi]

There is a serial over BLE (Nordic UART) example in the tree. Problem is, it seems it can't send more than 20 bytes on each transfer.
The code relies on BLE_ATTRIBUTE_MAX_VALUE_LENGTH which is set to 20. Increasing this value doesn't seem to have any effect (still sends 20 bytes max).
How to increase this limit?

arduino-BLEPeripheral/examples/serial/BLESerial.h

Line 31 in 161a416

uint8_t _rxBuffer[BLE_ATTRIBUTE_MAX_VALUE_LENGTH];