No information when requesting uploads in low power mode

[EddyLB]

When the iOS device is in low power mode, it does not upload photos to reduce battery consumption and a warning icon is displayed inside the "upload queue" button presented in the root album.

When the user requests the upload of a series of photos, he/she may not remember that the device is in low power mode and the app should presents a message for informing the user that the uploads are on hold.