Remove obsolete Group tag

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

liblzf.spec

@@ -3,7 +3,6 @@ Version:        3.6
 Release:        16%{?dist}
 Summary:        Small data compression library
 
-Group:          System Environment/Libraries
 License:        BSD or GPLv2+
 URL:            http://oldhome.schmorp.de/marc/liblzf.html
 Source0:        http://dist.schmorp.de/liblzf/liblzf-%{version}.tar.gz
@@ -23,7 +22,6 @@ is very, very fast, yet still written in portable C.
 
 %package        devel
 Summary:        Development files for %{name}
-Group:          Development/Libraries
 Requires:       %{name}%{?_isa} = %{version}-%{release}
 
 %if 0%{?el4}%{?el5}