Update p5-Date-Calc from version 6.2 to version 6.3

Pkgsrc changes:
- Adjust dependencies

Upstream changes:

What's new in version 6.3:
--------------------------
+  Changed "Mktime()" to use "POSIX::mktime()"
+  Fixed the bug that "Date::Calc::PP" was never tested
    when "Date::Calc::XS" is installed

(seb)