disable sled pin by default

Marlin/Marlin_main.cpp

@@ -2023,12 +2023,12 @@ inline void gcode_G28() {
 
       if (home_all_axis || homeZ) {
 
-        #ifdef Z_SAFE_HOMING    
+        #ifdef Z_SAFE_HOMING
 
           if (home_all_axis) {
 
             current_position[Z_AXIS] = 0;
-            sync_plan_position();         
+            sync_plan_position();
 
             //
             // Set the probe (or just the nozzle) destination to the safe homing point

Marlin/pins_SANGUINOLOLU_11.h

@@ -45,7 +45,7 @@
 #endif
 
 #ifdef Z_PROBE_SLED
-  #define SLED_PIN         27
+  #define SLED_PIN         -1
 #endif
 
 #ifdef NUM_SERVOS