Remove obsolete Group tag

References: https://fedoraproject.org/wiki/Changes/Remove_Group_Tag

sord.spec

@@ -6,7 +6,6 @@ Version:    0.16.2
 Release:    2%{?dist}
 Summary:    A lightweight Resource Description Framework (RDF) C library
 
-Group:      System Environment/Libraries
 License:    ISC
 URL:        http://drobilla.net/software/sord/
 Source0:    http://download.drobilla.net/%{name}-%{version}.tar.bz2
@@ -29,7 +28,6 @@ applications.
 
 %package devel
 Summary:    Development libraries and headers for %{name}
-Group:      Development/Libraries
 Requires:   %{name}%{_isa} = %{version}-%{release}
 
 %description devel