Core/Entities: Fix combat state setting when FFA PvP flag is set

Description:
Currently there is an issue, when you are in FFA areas, but you dont have PvP flag activated.

You should get the PvP-In-Combat delay timer, but instead you just get the usual timer as if you would not fight in PvP.

Reproduction:
1) Get two players in FFA area Gurubashi arena down in the battle area (.tele Gurubashi)

2) Fight each other

3) When stopping combat, the combat state will switch off immediately. But it is supposed to switch off after some delay, because it was a PvP fight.

Closes #11103

Signed-off-by: Duarte Duarte <dnpd.dd@gmail.com>