Merge pull request #7398 from fiveangle/bf_lcd_bed_level_requirements

Clarify LCD_BED_LEVELING requirements

Marlin/SanityCheck.h

   #if DISABLED(ULTIPANEL)
     #error "LCD_BED_LEVELING requires an LCD controller."
   #elif DISABLED(MESH_BED_LEVELING) && !(HAS_ABL && ENABLED(PROBE_MANUALLY))
-    #error "LCD_BED_LEVELING requires MESH_BED_LEVELING or PROBE_MANUALLY."
+    #error "LCD_BED_LEVELING requires MESH_BED_LEVELING or PROBE_MANUALLY with auto bed leveling enabled."
   #endif
 #endif