Do not unnecessarily break compatibility

...re 2c346d66 "tdf#39080 Hide Whitespace UI
option added to the View menu."

Change-Id: Ib2f364dba7a50854a11f004b42c7ee22ee10e48b
(cherry picked from commit 6efbd4bb)

offapi/com/sun/star/text/ViewSettings.idl

@@ -111,10 +111,6 @@ published service ViewSettings
      */
     [property] boolean ShowTabstops;
 
-    /** If this property is `TRUE`, whitespaces around pages are hidden.
-    */
-    [property] boolean HideWhitespace;
-
     /** If this property is `TRUE`, text boundaries are displayed.
      */
     [property] boolean ShowTextBoundaries;
@@ -263,6 +259,12 @@ published service ViewSettings
         @since LibreOffice 4.2
      */
     [optional, property] boolean ShowScrollBarTips;
+
+    /** If this property is `TRUE`, whitespaces around pages are hidden.
+
+        @since LibreOffice 5.1
+    */
+    [optional, property] boolean HideWhitespace;
 };
 
 }; }; }; };

offapi/type_reference/offapi.idl

@@ -15287,7 +15287,6 @@ module com {
      [property] boolean ShowTableBoundaries;
      [property] boolean ShowTables;
      [property] boolean ShowTabstops;
-     [property] boolean HideWhitespace;
      [property] boolean ShowTextBoundaries;
      [property] boolean ShowTextFieldBackground;
      [property] boolean ShowVertRuler;