PyDex and BLE_otas issue when using internal flash for OTA

[EdwinFairchild]

Issue

For some reason I have yet to figure out when using BLE_otas with
a smaller MTU (128) I get have to transmit really small packets of 20 bytes
which would take a really long time.

Workaround

You can enable Connection Parameter Updates in dats_main.c of the
BLE_otas project.
settings that I have tested for fast updates are shown below.

/*! configurable parameters for connection parameter update */
static const appUpdateCfg_t datsUpdateCfg = {
    10,
    /*! ^ Connection idle period in ms before attempting
    connection parameter update. set to zero to disable */
    (6), /*! Minimum connection interval in 1.25ms units */
    (9), /*! Maximum connection interval in 1.25ms units */
    0, /*! Connection latency */
    600, /*! Supervision timeout in 10ms units */
    5 /*! Number of update attempts before giving up */
};