Core/Misc: minor typo and codestyle fixes

- Replace NULL uses in new code with nullptr
- Fix wrong (accumulated) load time log when loading calendar invites
- Make Creature::CanRegenerateHealth const as its just a getter
- Mark OnlyOnceAreaTriggerScript::OnTrigger as final in case someone wants to override that (you are supposed to use protected _OnTrigger hook)

1 files changed, 1 insertions, 1 deletions

diff --git a/src/server/game/Events/GameEventMgr.cpp b/src/server/game/Events/GameEventMgr.cpp
index 3d991f77fd1..4c9e8df48fa 100644
--- a/src/server/game/Events/GameEventMgr.cpp
+++ b/src/server/game/Events/GameEventMgr.cpp
@@ -1758,7 +1758,7 @@ void GameEventMgr::SetHolidayEventTime(GameEventData& event)
 
     bool singleDate = ((holiday->Date[0] >> 24) & 0x1F) == 31; // Events with fixed date within year have - 1
 
-    time_t curTime = time(NULL);
+    time_t curTime = time(nullptr);
     for (int i = 0; i < MAX_HOLIDAY_DATES && holiday->Date[i]; ++i)
     {
         uint32 date = holiday->Date[i];