Merge pull request #3467 from AnHardt/Fix-Servo-without-endstop-probe

Fix-Servo-without-endstop/probe

Marlin/Conditionals.h

   #endif
 
   #if ( (HAS_Z_MIN && ENABLED(Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN)) || HAS_Z_PROBE ) && \
-    ( ENABLED(FIX_MOUNTED_PROBE) || defined(Z_ENDSTOP_SERVO_NR) || ENABLED(Z_PROBE_ALLEN_KEY) || ENABLED(Z_PROBE_SLED) )
+    ( ENABLED(FIX_MOUNTED_PROBE) || (Z_ENDSTOP_SERVO_NR >= 0) || ENABLED(Z_PROBE_ALLEN_KEY) || ENABLED(Z_PROBE_SLED) )
     #define HAS_Z_MIN_PROBE
   #endif