Log Message:
www/contao45: remove contao45 package

Remove www/contao45 package since Contao 4.5 were not distributed as
release tar files since version 4.5.11.  And it is EOL by release of
Contao 4.6 after 28th Aug 2018.

And Contao 4.6 is also only available via Contao Manager.  Please refer
<https://contao.org/download.html> in detail.