Update cran-comments

cran-comments.md

@@ -1,6 +1,12 @@
 This is a minor update that only corrects a test that would fail with the
 upcoming update of the tibble package, which this package imports. Therefore
-I haven't run any checks on downstream dependencies.
+I haven't run any checks on downstream dependencies. It also fixes the
+sanitizer warnings in timezone.c, thank you for pointing them out explicitly to
+me.
+
+Note that timezone.c included in readr is derived from the timezone.c shipped
+with R, therefore I opened a PR on the bug tracker with the same fix used here.
+(https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=17272)
 
 ## Test environments
 * local OS X install, R 3.3.1.