fix import options for blendshape

Assets/Meshes/sloth_head_blendshapes5.fbx.meta

     normalImportMode: 0
     tangentImportMode: 3
     normalCalculationMode: 0
-    legacyComputeAllNormalsFromSmoothingGroupsWhenMeshHasBlendShapes: 1
+    legacyComputeAllNormalsFromSmoothingGroupsWhenMeshHasBlendShapes: 0
     blendShapeNormalImportMode: 1
     normalSmoothingSource: 0
   importAnimation: 1