Remove obsolete Group tag

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

libgdiplus.spec

@@ -6,7 +6,6 @@ Version:        5.6
 Release:        2%{?dist}
 Summary:        An Open Source implementation of the GDI+ API
 
-Group:          System Environment/Libraries
 License:        MIT
 URL:            http://www.mono-project.com/Main_Page
 Source0:        http://download.mono-project.com/sources/%{name}/%{name}-%{version}.tar.gz
@@ -25,7 +24,6 @@ Project
 
 %package devel
 Summary: Development files for libgdiplus
-Group: Development/Libraries
 Requires: %{name} = %{version}-%{release}
 
 %description devel