Use valid coördinates for Unit::UpdateUnderWaterState instead of raw coördinates. Fixes another potential crash related to vmaps.

Updates issue #2748

--HG--
branch : trunk

src/server/game/Entities/Player/Player.cpp

@@ -6207,7 +6207,9 @@ bool Player::SetPosition(float x, float y, float z, float orientation, bool tele
         SetGroupUpdateFlag(GROUP_UPDATE_FLAG_POSITION);
 
     // code block for underwater state update
-    UpdateUnderwaterState(GetMap(), x, y, z);
+    // Unit::SetPosition() checks for validity and updates our coordinates
+    // so we re-fetch them instead of using "raw" coordinates from function params
+    UpdateUnderwaterState(GetMap(), GetPositionX(), GetPositionY(), GetPositionZ());
 
     if (GetTrader() && !IsWithinDistInMap(GetTrader(), INTERACTION_DISTANCE))
         GetSession()->SendCancelTrade();