Fixed shared build info code.

- The build info options of “two switches on an axis” and “homing init
lock” shared the same letter ‘L’. The former is now ’T’.

grbl/report.c

@@ -395,7 +395,7 @@ void report_build_info(char *line)
     serial_write('H');
   #endif
   #ifdef LIMITS_TWO_SWITCHES_ON_AXES
-    serial_write('L');
+    serial_write('T');
   #endif
   #ifdef ALLOW_FEED_OVERRIDE_DURING_PROBE_CYCLES
     serial_write('A');