nRF52: Fix gatt.setRSSIHandler on the first active connection

Author: gfwilliams

ChangeLog

@@ -11,6 +11,7 @@
             JIT: When referencing a built-in member function of a built-in (Math.*, E.*, PIN_NAME.*, etc) include address rather than looking up (#2398)
             nRF52 Central: Lower min connection interval from 20->7.5ms, max 200->1000ms (allows some extra devices to be connected to)
             Bangle.js2: Add optional long press button actions to `showPrompt` (#2656) 
+            nRF52: Fix gatt.setRSSIHandler on the first active connection
 
      2v27 : nRF5x: Ensure Bluetooth notifications work correctly when two separate connections use the same handle for their characteristics
             nRF5x: Remove handlers from our handlers array when a device is disconnected

targets/nrf5x/bluetooth.c

@@ -1280,7 +1280,7 @@ static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context) {
       case BLE_GAP_EVT_RSSI_CHANGED:  {
         int centralIdx = jsble_get_central_connection_idx(p_ble_evt->evt.gap_evt.conn_handle);
 #if CENTRAL_LINK_COUNT>0
-        if (centralIdx) {
+        if (centralIdx >= 0) {
           jsble_queue_pending(BLEP_RSSI_CENTRAL, (p_ble_evt->evt.gap_evt.params.rssi_changed.rssi&255) | (centralIdx<<8));
         }
 #endif