[import-main-matcher.cpp] when main matcher finalizes, refresh gui

If an import would add new transactions into the current register, and
the import dialog is cancelled, the GUI would show extra blank lines
for the deleted imported transactions. Refreshing GUI will ensure the
correct unchanged account register is shown.

gnucash/import-export/import-main-matcher.cpp

@@ -244,6 +244,8 @@ gnc_gen_trans_list_delete (GNCImportMainMatcher *info)
     g_list_free_full (info->new_strings, (GDestroyNotify)g_free);
 
     g_free (info);
+
+    gnc_gui_refresh_all ();
 }
 
 bool