Revert r46977. [ruby-core:63857] [Bug #10071]

The removed comment is useful to understand the behind idea to
solve the year 2038 problem.

The broken link is replaced to refer the internet archive.
0eed69757d (commitcomment-7166665)



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47179 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

time.c

@@ -1323,9 +1323,13 @@ gmtimew(wideval_t timew, struct vtm *result)
 static struct tm *localtime_with_gmtoff_zone(const time_t *t, struct tm *result, long *gmtoff, const char **zone);
 
 /*
- * This table finds the last month which starts at the same day of a week.
+ * The idea is borrowed from Perl:
+ * http://web.archive.org/web/20080211114141/http://use.perl.org/articles/08/02/07/197204.shtml
  *
- * It can be generated by the following program:
+ * compat_common_month_table is generated by the following program.
+ * This table finds the last month which starts at the same day of a week.
+ * The year 2037 is not used because:
+ * http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=522949
  *
  *  #!/usr/bin/ruby
  *