Null Sound Exploit Fix

#include <sdktools>
#pragma semicolon 1

public OnPluginStart()
{
    AddNormalSoundHook(NullSound);
}

public Action NullSound(int clients[MAXPLAYERS], int &numClients, char sample[PLATFORM_MAX_PATH], int &entity, int &channel, float &volume, int &level, int &pitch, int &flags, char soundEntry[PLATFORM_MAX_PATH], int &seed)
{
    if(StrContains(sample, "null.wav") != -1)
    {
        return Plugin_Stop;
    }
    return Plugin_Continue;
}