Bug 798966 - Uninitialised variable used in dialog-account-picker.c:d…

…ialog_response_cb()

The "placeholder" variable in dialog-account-picker.c:dialog_response_cb() may
be uninitialised before use if gtk_tree_selection_get_selected() returns
false.

Initialise it to true:
"jralls: The signal is blocked if the account is a placeholder, meaning
that one can't post splits to it. One also can't post splits to no account,
so the signal should be blocked in that case too."

gnucash/import-export/qif-imp/dialog-account-picker.c

@@ -360,7 +360,7 @@ dialog_response_cb (GtkDialog *dialog, gint response_id, gpointer user_data)
     QIFAccountPickerDialog * wind = user_data;
     GtkTreeModel *model;
     GtkTreeIter iter;
-    gboolean placeholder;
+    gboolean placeholder = TRUE;
 
     if (gtk_tree_selection_get_selected (gtk_tree_view_get_selection
                                         (wind->treeview), &model, &iter))