[test][1p] Fix field name reference solution

test/references/test_1pni_conduction_box-reference.vtu

@@ -2,7 +2,7 @@
 <VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">
   <UnstructuredGrid>
     <Piece NumberOfCells="200" NumberOfPoints="402">
-      <PointData Scalars="p" Vectors="velocity_liq">
+      <PointData Scalars="p" Vectors="velocity_liq (m/s)">
         <DataArray type="Float32" Name="p" NumberOfComponents="1" format="ascii">
           100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000
           100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000
@@ -39,7 +39,7 @@
           100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000 100000
           100000 100000 100000 100000 100000 100000
         </DataArray>
-        <DataArray type="Float32" Name="velocity_liq" NumberOfComponents="3" format="ascii">
+        <DataArray type="Float32" Name="velocity_liq (m/s)" NumberOfComponents="3" format="ascii">
           -1.17342e-09 8.52243e-19 0 -1.16807e-09 1.68217e-18 0 -1.17342e-09 8.52243e-19 0 -1.16807e-09 1.68217e-18 0
           -1.15247e-09 3.1127e-18 0 -1.15247e-09 3.1127e-18 0 -1.1275e-09 1.84323e-18 0 -1.1275e-09 1.84323e-18 0
           -1.09416e-09 3.84099e-18 0 -1.09416e-09 3.84099e-18 0 -1.05354e-09 1.9959e-18 0 -1.05354e-09 1.9959e-18 0