gnucash stable: Mostly revert "Bug 799249 - Crash while switch to recently opened file"

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/fb6e8d92 (commit)
	from  https://github.com/Gnucash/gnucash/commit/01f0d252 (commit)



commit fb6e8d927ef74921fd68e3f935a4375030fe97d5
Author: John Ralls <jralls at ceridwen.us>
Date:   Sun Oct 12 10:03:37 2025 -0700

    Mostly revert "Bug 799249 - Crash while switch to recently opened file"
    
    Leaving only nulling out the GncTreeModelAccount's root account pointer in its dispose
    function.



Summary of changes:
 gnucash/gnome-utils/gnc-tree-model-account.c   | 16 +++++++---------
 gnucash/gnome-utils/gnc-tree-view-account.c    | 23 +++--------------------
 gnucash/gnome/gnc-plugin-page-account-tree.cpp |  7 ++++---
 3 files changed, 14 insertions(+), 32 deletions(-)