Warning on Backup / Restore FileMenu open

Hi,

When pgAdmin fires the FileMenu while using the Backup Form (the second
time), the wxFileDialog is called with the filepath + filename instead of
just the filename that it expects as its third parameter. This throws up a
warning. The same thing happens with the Restore Form as well.

One such Debug report is given below.
Attached is a patch that passes just the FileName to wxFileDialog in both
the forms.

Regards,
*Robins Tharakan*

Debug report:
ASSERT INFO:
../src/common/filename.cpp(476): assert "volDummy.empty() &&
pathDummy.empty()" failed in Assign(): the file name shouldn't contain the
path

BACKTRACE:
[1] wxFileDialog::wxFileDialog(wxWindow*, wxString const&, wxString const&,
wxString const&, wxString const&, long, wxPoint const&, wxSize const&,
wxString const&)
[2] frmRestore::OnSelectFilename(wxCommandEvent&)
/projects/pgadmin/40_line_numbers_in_sql_view/7/pgadmin/./frm/frmRestore.cpp:136
[3] wxEvtHandler::ProcessEventIfMatches(wxEventTableEntryBase const&,
wxEvtHandler*, wxEvent&)
[4] wxEventHashTable::HandleEvent(wxEvent&, wxEvtHandler*)
[5] wxEvtHandler::ProcessEvent(wxEvent&)
[6] wxWindowBase::TryParent(wxEvent&)
[7] wxEvtHandler::ProcessEvent(wxEvent&)
[8] wxWindowBase::TryParent(wxEvent&)
[9] wxEvtHandler::ProcessEvent(wxEvent&)
[10] wxWindowBase::TryParent(wxEvent&)
[11] wxEvtHandler::ProcessEvent(wxEvent&)
[12] g_closure_invoke()
[13] g_signal_emit_valist()
[14] g_signal_emit()
[15] g_closure_invoke()
[16] g_signal_emit_valist()
[17] g_signal_emit()
[18] g_closure_invoke()
[19] g_signal_emit_valist()
[20] g_signal_emit()
[21] gtk_propagate_event()
[22] gtk_main_do_event()
[23] g_main_context_dispatch()
[24] g_main_loop_run()
[25] gtk_main()