Properly handle probe pin for BQ printers

Marlin/example_configurations/Hephestos/Configuration.h

 // Setting the wrong pin may have unexpected and potentially disastrous consequences.
 // Use with caution and do your homework.
 //
-//#define Z_MIN_PROBE_ENDSTOP
+#define Z_MIN_PROBE_ENDSTOP
 
 // Enable Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN to use the Z_MIN_PIN for your Z_MIN_PROBE.
 // The Z_MIN_PIN will then be used for both Z-homing and probing.
-#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
+//#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
 
 // To use a probe you must enable one of the two options above!
 

Marlin/example_configurations/Hephestos_2/Configuration.h

 // Setting the wrong pin may have unexpected and potentially disastrous consequences.
 // Use with caution and do your homework.
 //
-//#define Z_MIN_PROBE_ENDSTOP
+#define Z_MIN_PROBE_ENDSTOP
 
 // Enable Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN to use the Z_MIN_PIN for your Z_MIN_PROBE.
 // The Z_MIN_PIN will then be used for both Z-homing and probing.
-#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
+//#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
 
 // To use a probe you must enable one of the two options above!
 

Marlin/pins_BQ_ZUM_MEGA_3D.h

 #undef X_MAX_PIN
 #define X_MAX_PIN         79 //  2
 
+#undef Z_MIN_PROBE_PIN
+#define Z_MIN_PROBE_PIN   19 // IND_S_5V
+
 #undef Z_ENABLE_PIN
 #define Z_ENABLE_PIN      77 // 62
 
 
 #undef PS_ON_PIN             // 12
 #define PS_ON_PIN         81 // External Power Supply
-
-#if ENABLED(AUTO_BED_LEVELING_FEATURE)
-  #undef Z_MIN_PIN
-  #undef Z_MAX_PIN
-  #define Z_MIN_PIN       19 // IND_S_5V
-  #define Z_MAX_PIN       18 // Z-MIN Label
-#endif