fixed image-file testing

assets/deployer

@@ -301,7 +301,7 @@ prepare_image_publisher() {
 	echo -ne "setting docker auth config ..."
 	if [ "${dockerconfig}" == "" ];then
 		echo "failed! No auth config found"
-		echo "Please be sure to have provide the config via option docker-config for your build environment"
+		echo "Please be sure to provide the docker config via option --docker-config"
 		return 1
 	fi
 
@@ -362,7 +362,13 @@ import_image() {
 	local out
 	echo -ne "importing image..."
 
-	if [ ! -e ${image_file} ];then
+	if [ "${image_file}" == "" ];then
+		echo "failed! No image file specified"
+		echo "Make sure to specify an image file via --input"
+		return 1
+	fi
+
+	if [ ! -f $image_file ];then
 		echo "failed"
 		echo "${image_file} not found"
 		return 1