Permissions problems with /usr/local/var/urbackup

I have installed linux client 1.4.10 for urbackup with Mint 17.3.
I took the source code and successfully compiled without problem
Each time “start_urbackup_client” is starting (command in rc.local), permissions on directory “/usr/local/var/backup” are changed :
I had to change permissions after every reboot to

drwxr-xr-x 3 root root 4096 janv. 19 16:45 urbackup/

Nobody except root can read this directory where
password to connect to the server are stored.

Thanks in advance.

Best regards