Patch from Franck Joncourt for setting permissions via open()

Patch from Franck Joncourt for setting permissions via open()

[client+server] Applied patch from Franck Joncourt to remove unnecessary
chmod() call when creating client rc file and server replay cache file.
The permissions are now set appropriately via open(), and at the same
time this patch fixes a potential race condition since the previous code
used fopen() followed by chmod().