Fix provision help script DownloadURL.sh

The script neglected the result of the sha1 after download.
Even with a failure it exited nicely.

Change-Id: I6c0e25c2b764a0ad54acbe317eddf395a56d7f1c
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>

coin/provisioning/common/DownloadURL.sh

@@ -79,6 +79,10 @@ function DownloadURL {
                 echo "Failed downloading PKG from primary and alternative URLs"
                 exit 1;
             ;;
+            $ExceptionSHA1)
+                echo "Failed checksum on $targetFile."
+                exit 1;
+            ;;
         esac
     }
 }