flash-firmware: drop error on fail to connect

This error is already handled elsewhere.

src/components/notification-i18n.en.json

@@ -14,7 +14,6 @@
         }
     },
     "flashFirmware": {
-        "connectionFailed": "Could not connect to the hub. Restart the hub and try again.",
         "timedOut": "The hub took too long to respond. Restart the hub and try again.",
         "bleError": "There was a problem with Bluetooth.",
         "disconnected": "The hub was disconnected before flashing was completed. Restart the hub and try again.",

src/components/notification-i18n.ts

@@ -10,7 +10,6 @@ export enum MessageId {
     BleGattPermission = 'ble.gattPermission',
     BleGattServiceNotFound = 'ble.gattServiceNotFound',
     BleNoWebBluetooth = 'ble.noWebBluetooth',
-    FlashFirmwareConnectionFailed = 'flashFirmware.connectionFailed',
     FlashFirmwareTimedOut = 'flashFirmware.timedOut',
     FlashFirmwareBleError = 'flashFirmware.bleError',
     FlashFirmwareDisconnected = 'flashFirmware.disconnected',