fix display of middle displacement in gui

Magnetometer/magnetometer.pro

@@ -228,7 +228,7 @@ PostOperation {
       EndIf
       If(Flag_AnalysisType != 0)
         Print[ u, OnElementsOf Domain_Disp, File "res/u.pos"] ;
-        Print[ um, OnPoint {l/2,a/2,b/2}, Format Table, File "res/um_middle.txt",
+        Print[ um, OnPoint {l/2,a/2,b/2}, Format ValueOnly, File "res/um_middle.txt",
           SendToServer "Output/Middle diplacement [m]", Color "LightYellow" ];
         Echo[ Str["l=PostProcessing.NbViews-1; View[l].VectorType=5; ",
             "View[l].DisplacementFactor = 1e10;"],