Before opening (rendering) a nested modal map, make sure to save the parent
modal map in order to persist any structural uci changes, such as newly added
anonymous sections to prevent the nested map from operating on stale values
or ephemeral config section IDs.
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
(cherry picked from commit 3be479446bdeaf446468c5e7ac3b9bc49da023da)
ee5a7c6fc5