gnucash maint: [assistant-stock-transaction] guard against nullopts

[Christopher Lam]

Updated	 via  https://github.com/Gnucash/gnucash/commit/a43fa09d (commit)
	from  https://github.com/Gnucash/gnucash/commit/670902d5 (commit)



commit a43fa09d967472a5f25eda5d91afaecdaed3378f
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Fri May 6 08:59:45 2022 +0800

    [assistant-stock-transaction] guard against nullopts



Summary of changes:
 gnucash/gnome/assistant-stock-transaction.cpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)