Remove obsolete Group tag

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

amanith.spec

@@ -2,7 +2,6 @@ Name:          amanith
 Version:       0.3
 Release:       40%{?dist}
 Summary:       Crossplatform framework for 2d/3d vector graphics
-Group:         Development/Libraries
 License:       QPL
 URL:           http://www.amanith.org
 # Upstream no longer offers this code
@@ -32,7 +31,6 @@ system.
 
 %package devel
 Summary:       Development files for amanith
-Group:         Development/Libraries
 Requires:      glew-devel
 Requires:      %{name} = %{version}-%{release}