qtdragon -maxprobe should be a positive number

Author: c-morley

configs/sim/qtdragon/qtdragon_tool_probe/qtdragon_auto_tool_probe.ini

@@ -184,7 +184,7 @@ Z_MAX_CLEAR = 9.999
 # tool setter diameter for diameter probing
 DIAMETER = 25
 # maximum machine units to lower while probing
-MAXPROBE =  -40
+MAXPROBE =  40
 
 [AXIS_X]
 MIN_LIMIT = -0.001