Classification workflow: Display an Error message in case CRS information of vector and image layers do not agree

[Agustin Lobo]

(ref. #289)

Currently, in case CRS information of the image is absent, the classification process disregards the CRS info entered by the user when prompted and simply does not proceed with the classification, not issuing any error message.

Please issue an error message such as “ERROR: CRS information of input layers do not agree” (and best if the message is followed by both CRS infos as read by the classification process) in those cases.