Disable THERMAL_PROTECTION_BED with no sensor

Marlin/Conditionals.h

 
   #define HAS_TEMP_HOTEND (HAS_TEMP_0 || ENABLED(HEATER_0_USES_MAX6675))
 
+  #define HAS_THERMALLY_PROTECTED_BED (HAS_TEMP_BED && HAS_HEATER_BED && ENABLED(THERMAL_PROTECTION_BED))
+
   /**
    * Helper Macros for heaters and extruder fan
    */