OSSNull doesn't properly filter servers based on settings

OSSNull doesn't properly account for bShouldAdvertise or bAllowJoinInProgress.

These should be updated in OnValidQueryPacketReceieved.

(Note, bShouldAdvertise is explicitly ignored in LAN matches).

1. Download and Compile the attached project.
2. Launch two instances (don't use the editor).
3. In the first instance, Press 1 to create and start a new session.
4. In the second instance, Press 2 to find sessions.
5. In the first instance, Press 3 to toggle Joinable in Progress
6. In the second instance, Press 2 to find sessions.

Expected: After the first query 1 session is found. After the second (Joinable in Progress was toggled), no sessions are found.

Actor: After both queries, sessions are found.