dfu: kconfig: Fix styling

Fixes this styling to be valid

Signed-off-by: Jamie McCrae <spam@helper3000.net>
diff --git a/subsys/dfu/Kconfig b/subsys/dfu/Kconfig
index 053413b..77882ca 100644
--- a/subsys/dfu/Kconfig
+++ b/subsys/dfu/Kconfig
@@ -93,6 +93,7 @@
 source "subsys/logging/Kconfig.template.log_config"
 
 if !MCUBOOT
+
 config UPDATEABLE_IMAGE_NUMBER
 	int "Number of updateable images"
 	default 1
@@ -100,6 +101,7 @@
 	help
 	  If value is set to 2 or greater then, this enables support needed when
 	  application is combined with MCUboot multi-image boot.
+
 endif
 
 endif # IMG_MANAGER