Fix here too, avoids pointless rebuild

Updated comment in stdlib_flags.h

src/stdlib_flags.h

@@ -1,6 +1,5 @@
 #include "util/options.h"
 
-// this comment has been updated 1 time(s)
 namespace lean {
 options get_default_options() {
     options opts;

stage0/src/stdlib_flags.h

@@ -1,6 +1,5 @@
 #include "util/options.h"
 
-// this comment has been updated 1 time(s)
 namespace lean {
 options get_default_options() {
     options opts;