api: corrected mesh data maxlen, was on old value
api: corrected mesh data maxlen, was on old value

mrquincle/nRF51-ble-bcast-mesh,mrquincle/nRF51-ble-bcast-mesh,mrquincle/nRF51-ble-bcast-mesh,mrquincle/nRF51-ble-bcast-mesh