Items in Panelize mode disappear after several rounds of Ctrl+O

[zaytsev]

From ​https://github.com/MidnightCommander/mc/issues/57:

MC forget items in 'Panelize'.

1) Add something to 'Panelize'. It works with 'Find file' and 'External panelize' too.
2) Press C-o several times(or run some console command)
3) Panel is now empty

Reproduce:
1. on the left panel, get into a folder which has for example 2 folders which the right panel has: eg. dev and bin
2. cd / on the right panel (because it has dev and bin folders)
3. make sure left panel and right panel are in different current folders! (but both have (at least) 2 same named folders)
4. put cursor on left panel anywhere
5. Alt+shift+/ to open find file dialog and find * files recursively starting at . Using shell paterns
(EDIT: find recursively is not necessary)
6. press l to Panelize
7. press C-o four times

I was able to reproduce it on latest master by creating a folder that contains subfolders "dev", "bin" and "test" and following the procedure above. After few panel switches with Ctrl+O, "test" disappears.