[22929] Finally fix the maddening long waiting times after clicking "Ok" in the import matcher window.

Turns out we were simply missing a suspend_gui_refresh call before actually
processing the results. Sigh.

(Can go into 2.4 because the bugfix is so surprisingly simple.)

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/branches/2.4@22930 57a11ea4-9604-0410-9ed3-97b8803252fd