[aur-general] remove request [celtx-bin64]

[member graysky]

I adopted the 'celtx-bin' package and updated it to the latest version as
well as enhanced the support to cover both i686 and x86_64.  There is also
a package called celtx-bin64 which is now redundant.  The maintainer of
this package agrees that we should remove it.
https://aur.archlinux.org/packages.php?ID=46977