Ticket #3669: cannot change directory in the active panel
...after changing VFS in the passive one.
Steps to reproduce:
1. Make left panel active.
2. Press F9 to open menu, select 'Right', then 'FTP link...'
3. Insert a valid FTP URL and press OK (or Enter). Wait for finish of FTP
directory reading.
4. Left panel is still active. Try to change CWD here by pressing Enter
or using command line.
Result: error messages 'ftpfs: CWD failed' and 'Cannot change directory'
or 'Cannot chdir to...'.
The problem: when VFS is changed in the passive panel, VFS CWD is
changed accordingly. Then active panel tries use the new VFS CWD.
The solution: restore VFS CWD after changing VFS in the passive panel.
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>