wxLua: upload files with wxFtp

local ftp = wx.wxFTP()
local ftpAddress = wx.wxIPV4address()
ftpAddress:Service( "ftp" )
ftpAddress:Hostname( "ftp.example.com" )
ftp:Connect( ftpAddress )
local out1 = ftp:GetOutputStream( "foo" )
out1:Close()
local out2 = ftp:GetOutputStream( "bar" )
out2:Close() -- here out2 is nil

local ftp = wx.wxFTP()
local ftpAddress = wx.wxIPV4address()
ftpAddress:Service( "ftp" )
ftpAddress:Hostname( "ftp.example.com" )
ftp:Connect( ftpAddress )
local out1 = ftp:GetOutputStream( "foo" )
out1 = nil
collectgarbage("collect")  -- force full garbage collection
local out2 = ftp:GetOutputStream( "bar" )
out2 = nil
collectgarbage("collect")