Don't set group tags

They are unused in Fedora.

clutter-gtk.spec

@@ -8,7 +8,6 @@ Version:        1.8.4
 Release:        1%{?dist}
 Summary:        A basic GTK clutter widget
 
-Group:          Development/Languages
 License:        LGPLv2+
 URL:            http://www.clutter-project.org
 Source0:        http://download.gnome.org/sources/clutter-gtk/1.8/clutter-gtk-%{version}.tar.xz
@@ -27,7 +26,6 @@ GTK+ widgets inside the stage.
 
 %package devel
 Summary:        Clutter-gtk development environment
-Group:          Development/Libraries
 Requires:       %{name}%{?_isa} = %{version}-%{release}
 
 %description devel