gnucash maint: Fix crashes in test-engine on Arch Linux.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/1020bde8 (commit)
	from  https://github.com/Gnucash/gnucash/commit/946fbb12 (commit)



commit 1020bde89c77f70cee6cc8181ead96e8fade47aa
Author: John Ralls <jralls at ceridwen.us>
Date:   Tue Mar 14 10:16:42 2023 -0700

    Fix crashes in test-engine on Arch Linux.
    
    Root cause is mutating a list while it's iterating. We're able to
    protect it in two cases, have to copy it in xaccTransScrubGainsDate.



Summary of changes:
 libgnucash/engine/Account.cpp                | 6 ++++++
 libgnucash/engine/Transaction.c              | 4 +++-
 libgnucash/engine/test/utest-Transaction.cpp | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)