No changes, just sort richtext files in files.bkl.

No changes, just sort richtext files in files.bkl.

Sort RICHTEXT_{SRC,HDR} contents in alphabetical order, just as it's done for
all the other files list and to make it easier to check if a file already
occurs in these lists or not.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67715 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775