Removed redundent text in celcius to kelvin icon (#4466)

Author: qnikil7

Modelica/Thermal/HeatTransfer/Celsius/ToKelvin.mo

@@ -10,14 +10,6 @@ equation
   annotation (
     Icon(coordinateSystem(preserveAspectRatio=true, extent={{-100,-100},{
             100,100}}), graphics={
-        Text(
-          extent={{54,-88},{114,-148}},
-          textColor={64,64,64},
-          textString="degC"),
-        Text(
-          extent={{194,-88},{254,-148}},
-          textColor={64,64,64},
-          textString="K"),
         Text(
           extent={{-100,60},{-40,0}},
           textColor={64,64,64},