Fixed: connecting to a server through the internal server browser (or after using the "restart" CCMD) caused the game to crash.

If a client connects to a server through the internal server browser, or uses the restart CCMD to connect to one, their game sometimes crashed. This is because the VoIP panel and country flag column had FTexture pointers that were no longer valid after the restart. It's probably best if everything on the scoreboard (e.g. columns and margins) is cleared when the restart is initiated, and if the speaker icon on the VoIP panel is always looked up during a refresh (technically this is less optimized than initializing the speaker icon's pointer only once, but the extra overhead shouldn't be an issue).