Search spam detected issue after AirDC v4.21 "update"

I'm posting this bug in the event that Luadch doesn't have some sort of search spam limitation and that's what's partially responsible for the following message:
`*** Search spam detected from () (severe). The hub will be disconnected in order to preserve system resources. If you continue receiving this error, it may indicate that the hub utilizes its users in a DDoS attack.`

Ever since the latest AirDC++ v4.21 update, the previous error has been constantly reported by many users.
In some cases just the message is received but in other situations, entire hub userlists are being disconnected simultaneously.
I posted this issue on the AirDC bug tracker too because I have a feeling it's a combination of both projects not playing well with each other: [Search spam detected (False Positive Behavior)](https://github.com/airdcpp/airdcpp-windows/issues/94)

Since I have little faith the AirDC dev is going to remove or change his client's behavior, I'm hoping Luadch devs will look into a possible solution for this.

For some reason the AirDC dev keeps updating his client to address issues that don't seem to be affecting very many users and in the process causes inconvenient client behavior for the majority of users, then blames Luadch 😂.
Remember [SECURITY WARNING: received a DSCH message that should have been sent to a different user.](https://github.com/airdcpp/airdcpp-windows/issues/76)?
I feel sorry that AirDC "updates" address none of the community's main feature requests and bugs and instead addresses problems no one is experiencing, which just causes more work for Luadch.
/rant

No source files or tests are named. Start by reproducing the search-spam false positive with AirDC++ v4.21 and inspect Luadch's search-spam handling; done means legitimate users are no longer incorrectly disconnected while genuine spam remains controlled.

Written by the indexing model from the issue text.