Rainer Loritz noticed that the Telnet environment box is not cleared

when loading a new session. Oops!

[originally from svn r1171]

windlg.c

@@ -663,6 +663,7 @@ static void init_dlg_ctrls(HWND hwnd, int keepsess)
 		     IDC_LSTATXAPN);
     {
 	char *p = cfg.environmt;
+	SendDlgItemMessage(hwnd, IDV_ENVLIST, LB_RESETCONTENT, 0, 0);
 	while (*p) {
 	    SendDlgItemMessage(hwnd, IDC_ENVLIST, LB_ADDSTRING, 0,
 			       (LPARAM) p);