Quote template values in .openrc

This is to keep the shell from performing variable expansion when sourcing the
.openrc file. E.g. when OS_PASSWORD contains '$'.

related to: https://bugzilla.suse.com/show_bug.cgi?id=896750

(cherry picked from commit 854de3f5dfa2a6e2ba817ab2e2819205c2648381)
Merge pull request #244 from rhafer/backports

Quote template values in .openrc