Clear PVP option flag on logout

Client no longer thinks that PvP flag is on when it clearly isn't.
The flag itself is not used properly yet, to be improved in the future.

(based on cmangos/mangos-wotlk@2da5b4387)

Signed-off-by: Xfurry <xfurry.cmangos@outlook.com>

src/game/Player.cpp

@@ -2918,7 +2918,7 @@ void Player::InitStatsForLevel(bool reapplyMods)
     SetFlag(UNIT_FIELD_FLAGS_2, UNIT_FLAG2_REGENERATE_POWER); // must be set
 
     // cleanup player flags (will be re-applied if need at aura load), to avoid have ghost flag without ghost aura, for example.
-    RemoveFlag(PLAYER_FLAGS, PLAYER_FLAGS_AFK | PLAYER_FLAGS_DND | PLAYER_FLAGS_GM | PLAYER_FLAGS_GHOST);
+    RemoveFlag(PLAYER_FLAGS, PLAYER_FLAGS_AFK | PLAYER_FLAGS_DND | PLAYER_FLAGS_GM | PLAYER_FLAGS_GHOST | PLAYER_FLAGS_IN_PVP);
 
     RemoveStandFlags(UNIT_STAND_FLAGS_ALL);                 // one form stealth modified bytes
     RemoveByteFlag(UNIT_FIELD_BYTES_2, 1, UNIT_BYTE2_FLAG_FFA_PVP);