Allow changing max connections by only changing nimconfig setting.

This allows the max connections to be altered by only changing
the CONFIG_BT_NIMBLE_MAX_CONNECTIONS value in nimconfig.h.

Changes in sdkconfig.h are no longer required to use this.

Author: h2zero

src/esp-hci/src/esp_nimble_hci.c

@@ -470,6 +470,7 @@ esp_err_t esp_nimble_hci_and_controller_init(void)
     esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT);
 
     esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
+    bt_cfg.ble_max_conn = CONFIG_BT_NIMBLE_MAX_CONNECTIONS;
 
     if ((ret = esp_bt_controller_init(&bt_cfg)) != ESP_OK) {
         return ret;