Missing friendlyfire after previous commit

[UnrealKaraulov]

Fix #806

[wopox1337]

Perhaps another solution would be better

ReGameDLL_CS/regamedll/dlls/multiplay_gamerules.cpp

Lines 3691 to 3704 in 889edc8

	BOOL EXT_FUNC CHalfLifeMultiplay::__API_HOOK(FPlayerCanTakeDamage)(CBasePlayer *pPlayer, CBaseEntity *pAttacker)
	{
	if (!pAttacker || PlayerRelationship(pPlayer, pAttacker) != GR_TEAMMATE)
	{
	return TRUE;
	}
	if (friendlyfire.value != 0.0f || pAttacker == pPlayer)
	{
	return TRUE;
	}
	return FALSE;
	}

[wopox1337]

If I understand it correctly, it should fit.