added/changed a Newton criterion

lecture/mm/heatpipe/heatpipe.input

 [TimeLoop]
 DtInitial = 1 # [s]
-TEnd = 2.2e10 # [s]
-EpisodeLength = 1.e8
+TEnd = 2.2e12 # [s]
+EpisodeLength = 1.e10
 
 [Grid]
 File = ./grids/heatpipe.dgf
@@ -21,3 +21,6 @@ EnableGravity = false
 SolidHeatCapacity = 700
 SolidDensity = 2600
 SolidThermalConductivity = 2.8
+
+[Newton]
+MaxRelativeShift = 1e-6