Core/Spells: Normalize Z for last point in a charge path

Normalize the new point that 124398feef adds to a charge path.

(cherry picked from commit e5258f92c8057d453b890976eb18e98e6de96d07)

src/server/game/Movement/PathGenerator.cpp

@@ -925,6 +925,7 @@ void PathGenerator::ReducePathLenghtByDist(float dist)
             float step = dist / len;
             // same as nextVec
             _pathPoints[i + 1] -= diffVec * step;
+            _sourceUnit->UpdateAllowedPositionZ(_pathPoints[i + 1].x, _pathPoints[i + 1].y, _pathPoints[i + 1].z);
             _pathPoints.resize(i + 2);
             break;
         }