downloads don't proceed after start without any feedback

[Karl-Philipp Richter]

`midori` does not proceed with downloads after they are started (after the storage location has been set in the dialog), i.e. there's no noticable progress and no network traffic according to `gnome-system-monitor`. I verified that with

    http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18.5-vivid/linux-headers-3.18.5-031805_3.18.5-031805.201501292218_all.deb

and

    https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.18.5.tar.xz

which are independent domains afaik and both downloads work with `firefox` and `chromium-browser`.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: midori 0.4.3+dfsg-0.1
Uname: Linux 3.18.5-031805-generic x86_64
ApportVersion: 2.14.7-0ubuntu8.1
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Jan 31 01:32:19 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-01-26 (4 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: midori
UpgradeStatus: No upgrade log present (probably fresh install)