Merge pull request #3556 from philfifi/fix_pullup

Fix bug in pullups handling for Z_MIN_PROBE

Marlin/Conditionals.h

     #if ENABLED(USE_ZMIN_PLUG)
       #define ENDSTOPPULLUP_ZMIN
     #endif
-    #if ENABLED(DISABLE_Z_MIN_PROBE_ENDSTOP)
+    #if DISABLED(DISABLE_Z_MIN_PROBE_ENDSTOP)
       #define ENDSTOPPULLUP_ZMIN_PROBE
     #endif
   #endif