FIX in DisplayLineGraph, in case min==max it gives div by zero. Fixed scaling autocalculation.

Author: AlanFromJapan

library/lcd/lcd_comm.py

@@ -420,7 +420,7 @@ def DisplayLineGraph(self, x: int, y: int, width: int, height: int,
 
         step = width / len(values)
         # pre compute yScale multiplier value
-        yScale = height / (max_value - min_value)
+        yScale = (height / (max_value - min_value)) if (max_value - min_value) != 0 else 0
 
         plotsX = []
         plotsY = []