Update libsoup24 to 2.26.0.

Changes in libsoup from 2.25.91 to 2.26.0:

	* Temporarily disable libproxy support to work around a bug in
          its gnome plugin that causes gvfsd-http (and probably
          eventually other apps) to crash. [#571527]. For now,
          SoupProxyResolverGNOME uses only GConf. To be fixed in
          2.26.1

	* Fixed a bug that showed up in WebKit, where if many messages
          were queued all at once to a server that doesn't support
          persistent connections, some of the requests will get lost.
          #574365, reported by Xan Lopez.

	* Fixed SoupServer to support using SOUP_ENCODING_EOF, so you
          can stream responses of unknown length to HTTP/1.0 clients.
          [#572153]. Added a regression test for this, and for chunked
          and Content-Length-based streaming.

	* Fixed several bugs that prevented SoupCookieJarSqlite from
          working. [#572409, patch from Xan Lopez]

	* Added G_{BEGIN,END}_DECLS guards to public headers that were
          missing it. (Xan Lopez)

	* Misc gtk-doc improvements


(jmcneill)