[CliptonHeist]

Untested, lemme know if this does/doesn't work.

PHP Code:

#include <sourcemod>

#pragma semicolon 1
#pragma newdecls required

public void OnPluginStart()
{
    HookEvent("round_start", Event_RoundStart);
    HookEvent("player_death", Event_PlayerDeath, EventHookMode_Post);
}

public void Event_RoundStart(Event event, const char[] name, bool dontBroadcast)
{
    SetConVarInt(FindConVar("mp_ignore_round_win_conditions"), 1);
}

public void Event_PlayerDeath(Event event, const char[] name, bool dontBroadcast)
{
    bool bDead = true;
    for(int i = 1; i <= MaxClients; i++)
    {
        if(!IsValidClient(i)) continue;

        if(IsPlayerAlive(i)) 
        {
            bDead = false;
            break;
        }
    }

    if(bDead) SetConVarInt(FindConVar("mp_ignore_round_win_conditions"), 0);
}

stock bool IsValidClient(int client)
{
    return client >= 1 && 
    client <= MaxClients && 
    IsClientConnected(client) && 
    IsClientAuthorized(client) && 
    IsClientInGame(client);
}