Fix use of uninitialised value in gnc_split_register_load()

The column value appears to be unused by gnc_split_register_show_trans()
but vc_loc.virt_col is an int so its value will not have been default
initialised. Set it to 0 to be consistent with other callers.

gnucash/register/ledger-core/split-register-load.c

@@ -902,6 +902,7 @@ gnc_split_register_load (SplitRegister* reg, GList* slist,
     {
         VirtualCellLocation vc_loc;
         vc_loc.virt_row = 0;
+        vc_loc.virt_col = 0;
         gnc_split_register_show_trans (reg, vc_loc);
     }
     else