Crash after copying plugins while the daemon is running

[paulbarbu]

1. Start the daemon (have some enabled plugins)
2. Use a plugin
3. Copy the plugins from the build dir to the pluginroot
4. Use the plugin initially used at 2.
5. Crash:
   Thread (pooled)[8182]: segfault at 0 ip (null) sp b44fe9ac error 4 in http-daemon[8048000+17000]

[paulbarbu]

Interestingly this happens after the latest changes that load the plugins at startup only.
And it doesn't happend when I delete the files. (step 3)