Don't set group tags

They are unused in Fedora.

gtk3.spec

@@ -22,7 +22,6 @@ Release: 1%{?dist}
 Summary: The GIMP ToolKit (GTK+), a library for creating GUIs for X
 
 License: LGPLv2+
-Group: System Environment/Libraries
 URL: http://www.gtk.org
 Source0: http://download.gnome.org/sources/gtk+/3.21/gtk+-%{version}.tar.xz
 
@@ -115,7 +114,6 @@ applications, the overall memory consumption is reduced as well.
 
 %package immodules
 Summary: Input methods for GTK+
-Group: System Environment/Libraries
 Requires: gtk3%{?_isa} = %{version}-%{release}
 # for im-cedilla.conf
 Requires: gtk2-immodules%{?_isa}
@@ -126,7 +124,6 @@ are shipped as part of GTK+ 3.
 
 %package immodule-xim
 Summary: XIM support for GTK+
-Group: System Environment/Libraries
 Requires: gtk3%{?_isa} = %{version}-%{release}
 
 %description immodule-xim
@@ -134,7 +131,6 @@ The gtk3-immodule-xim package contains XIM support for GTK+ 3.
 
 %package devel
 Summary: Development files for GTK+
-Group: Development/Libraries
 Requires: gtk3%{?_isa} = %{version}-%{release}
 Obsoletes: gtk3-engines-devel <= 2.91.5-5.fc15
 
@@ -146,7 +142,6 @@ gtk3-devel-docs package.
 
 %package devel-docs
 Summary: Developer documentation for GTK+
-Group: Development/Libraries
 Requires: gtk3 = %{version}-%{release}
 
 %description devel-docs
@@ -155,7 +150,6 @@ widget toolkit.
 
 %package tests
 Summary: Tests for the %{name} package
-Group: Development/Libraries
 Requires: %{name}%{?_isa} = %{version}-%{release}
 
 %description tests
@@ -339,6 +333,7 @@ gtk-query-immodules-3.0-%{__isa_bits} --update-cache
 %changelog
 * Tue Aug 30 2016 Kalev Lember <klember@redhat.com> - 3.21.5-1
 - Update to 3.21.5
+- Don't set group tags
 
 * Wed Jul 27 2016 Kalev Lember <klember@redhat.com> - 3.21.4-2
 - Install dconf gsettings backend by default (#1351236)