fix: temlate name from linux to linux-snmp

Service is no more bind to host with linux-snmp name.
Change libexec path

Script should now be installed in /var/lib/shinken/libexec directory.
Change path from /usr/local/nagios/libexec to /var/lib/shinken/libexec.

This will prevent the following error
  Can't locate utils.pm in @INC
Merge pull request #4 from AddOnline/master

Update host name and path