Fix build with LA_LIVE_K

Do not check for LA_LIVE_K in messages.c (Configuration_adv.h is not
included here).

Rely on the linker to drop the symbol when LA_LIVE_K is disabled.

Firmware/messages.c

@@ -168,7 +168,5 @@ const char MSG_OCTOPRINT_CANCEL[] PROGMEM_N1 = "// action:cancel"; ////
 const char MSG_FANCHECK_EXTRUDER[] PROGMEM_N1 = "Err: EXTR. FAN ERROR"; ////c=20
 const char MSG_FANCHECK_PRINT[] PROGMEM_N1 = "Err: PRINT FAN ERROR"; ////c=20
 const char MSG_M112_KILL[] PROGMEM_N1 = "M112 called. Emergency Stop."; ////c=20
-#ifdef LA_LIVE_K
 const char MSG_ADVANCE_K[] PROGMEM_N1 = "Advance K:"; ////c=13
-#endif
 const char MSG_POWERPANIC_DETECTED[] PROGMEM_N1 = "POWER PANIC DETECTED"; ////c=20