Update broken external link

Updated a broken link reference that was moved from:
・http://support.microsoft.com/kb/244664   to  https://docs.microsoft.com/en-us/office/troubleshoot/excel/two-digit-year-numbers#the-2029-rule
・http://www.filemaker.com/12help/html/add_view_data.4.21.html     to    https://fmhelp.filemaker.com/help/18/fmp/en/index.html#page/FMP_Help/dates-with-two-digit-years.html

Author: rio-yo

src/lib/dates.js

@@ -111,14 +111,14 @@ var MIN_MS, MAX_MS;
  * you can use a gregorian date string prefixed with 'G' or 'g'.
  *
  * Where to cut off 2-digit years between 1900s and 2000s?
- * from http://support.microsoft.com/kb/244664:
+ * from https://docs.microsoft.com/en-us/office/troubleshoot/excel/two-digit-year-numbers#the-2029-rule:
  *   1930-2029 (the most retro of all...)
  * but in my mac chrome from eg. d=new Date(Date.parse('8/19/50')):
  *   1950-2049
  * by Java, from http://stackoverflow.com/questions/2024273/:
  *   now-80 - now+19
  * or FileMaker Pro, from
- *      http://www.filemaker.com/12help/html/add_view_data.4.21.html:
+ *      https://fmhelp.filemaker.com/help/18/fmp/en/index.html#page/FMP_Help/dates-with-two-digit-years.html:
  *   now-70 - now+29
  * but python strptime etc, via
  *      http://docs.python.org/py3k/library/time.html: