Use cygdrive prefix for secrets file path.

[ossama-othman]

BackupPC server attempts to access client modules listed in the sample
rsyncd.conf file shipped with cygwin-rsyncd will be denied because of
the use of native Windows paths in the secrets file configuration,
e.g. c:/rsyncd/rsyncd.secrets, presumably because the RsyncServer
process can't find the file. Using the "cygdrive" prefix in the path,
i.e. /cygdrive/c/rsyncd/rsyncd.secrets, allows module access to
succeed.

[ossama-othman]

According to the Cygwin documentation use of native Windows paths is inadvisable, and may not necessarily work for Cygwin applications (like RsyncServer?). If native Windows paths are indeed problematic for Cygwin applications, shouldn't all of the paths in the sample rsyncd.conf use the cygdrive prefix?

At the very least, using the cygdrive prefix for my secrets file path addressed BackupPC server access to my client modules.

[craigbarratt]

Thanks for submitting this fix.