org-table: Add missing keywords to a defcustom

* lisp/org-table.el (org-table-duration-hour-zero-padding):
  Add :package-version and :safe. Fix :version and docstring.

etc/ORG-NEWS

@@ -250,6 +250,12 @@ to ~org-file-contents~.
 Using ~C-c C-c~ on any keyword (like ~#+SETUPFILE~) will reset the
 that file cache.
 
+*** New option : ~org-table-duration-hour-zero-padding~
+This variable allow computed durations in tables to be zero-padded.
+
+*** New mode switch for table formulas : =U=
+This mode omits seconds in durations.
+
 ** Removed functions
 
 *** Org Timeline

lisp/org-table.el

@@ -306,11 +306,13 @@ a single formula."
 		 (symbol :tag "HH:MM  " 'hh:mm)))
 
 (defcustom org-table-duration-hour-zero-padding t
-  "Non-nil means, hours in table duration computations should be zero-padded.
+  "Non-nil means hours in table duration computations should be zero-padded.
 So this is about 08:32:34 versus 8:33:34."
   :group 'org-table-calculation
-  :version "24.1"
-  :type 'boolean)
+  :version "26.1"
+  :package-version '(Org . "9.1")
+  :type 'boolean
+  :safe #'booleanp)
 
 (defcustom org-table-formula-field-format "%s"
   "Format for fields which contain the result of a formula.