gnucash maint: [report-utilities] use fold for gnc:accounts-count-splits

[Christopher Lam]

Updated	 via  https://github.com/Gnucash/gnucash/commit/34be3c8b (commit)
	from  https://github.com/Gnucash/gnucash/commit/3a6d1ea6 (commit)



commit 34be3c8b14c97fd06a2a113d2a960f2089e3a279
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Sun Jan 29 14:25:41 2023 +0800

    [report-utilities] use fold for gnc:accounts-count-splits
    
    previous definition would build intermediate lists for each step. also
    handles the null account-list.



Summary of changes:
 gnucash/report/report-utilities.scm           | 2 +-
 gnucash/report/test/test-report-utilities.scm | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)