Update reference test for tiff images

That's because TIFF images are clamped instead of zeroed when evaluated outside its domain

test/reference/test_tiff-00000.vtu

@@ -4,7 +4,7 @@
     <Piece NumberOfCells="256" NumberOfPoints="145">
       <PointData Scalars="u">
         <DataArray type="Float32" Name="u" NumberOfComponents="1" format="binary">
-          RAIAAA==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
+          RAIAAA==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
         </DataArray>
       </PointData>
       <Points>