fix: Fix the regular expression for the daemon's notification subscription

[gkc]

- What I did
fix: Fix the regular expression for the daemon's notification subscription so if device name is 'xyz' then it will handle notifications to 'ping.xyz.sshnp' or 'xyz.sshnp' but not to 'ping.wxyz' or 'wxyz.sshnp'

Fixes #1485

- How I did it
See commits

- How to verify it

• Run two daemons, one with device name xyz and another with device name wxyz
• Run npt or sshnp client with device name wxyz
• If using sshnpd from releases up to now, both daemons will receive the request; and if they are using policy then both will send a request to the policy server. (Note that, ultimately, the daemon for xyz will not actually try to handle the request, which is why this bug has slipped through the net until now)
• If using sshnpd built from this branch, the request will only be received by the intended recipient daemon.