Remove account on logout.

server/src/auth_provider.rs

@@ -42,6 +42,8 @@ impl AuthProvider {
         }
     }
 
+    pub fn logout(&mut self, username: &str) { self.accounts.retain(|_, v| v != username); }
+
     pub fn query(&mut self, username_or_token: String) -> Result<(), RegisterError> {
         // Based on whether auth server is provided or not we expect an username or
         // token

server/src/sys/message.rs

@@ -293,6 +293,7 @@ impl<'a> System<'a> for Sys {
                         None,
                         ServerMsg::broadcast(format!("{} went offline.", &player.alias)),
                     ));
+                    accounts.logout(&player.alias);
                 }
                 server_emitter.emit(ServerEvent::ClientDisconnect(entity));
                 client.postbox.send_message(ServerMsg::Disconnect);