GNOME: cannot compile with webkit2gtk-3.0
Issue generated from Tuleap's migration script. Originally submitted by: Stepan Salenikovich (ssalenik)
webkit2gtk-3.0 provides version 2.4.x, but commit 32b8dd6b introduced the use of WebKitUserStyleSheet which is only available as of 2.6: https://webkitgtk.org/reference/webkit2gtk/2.6.3/webkit2gtk-WebKitUserContent.html
Either we need to provide an alternative code path which is compatible with 2.4, or else indicate that webkit2gtk-4.0 is required. Note that the later would mean dropping support for ubuntu 14.04.