Drop no longer needed and too open crossdomain.xml

It allowed Flash apps on any domain to make requests on
behalf of a signed in user.

Thanks to Oliver Beg for the hint.

Changelog.md

@@ -87,6 +87,7 @@ This is disabled by default since it requires the installation of additional pac
 * Handle unset user agent when signing out [#5316](https://github.com/diaspora/diaspora/pull/5316)
 * More robust URL parsing for oEmbed and OpenGraph [#5347](https://github.com/diaspora/diaspora/pull/5347)
 * Fix Publisher doesn't expand while uloading images [#3098](https://github.com/diaspora/diaspora/issues/3098)
+* Drop unneeded and too open crossdomain.xml
 
 ## Features
 * Don't pull jQuery from a CDN by default [#5105](https://github.com/diaspora/diaspora/pull/5105)

public/crossdomain.xml

@@ -1,3 +0,0 @@
-<cross-domain-policy>
-     <allow-access-from domain="*" to-ports="*" />
-</cross-domain-policy>