Remove obsolete Group tag

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

lwp.spec

@@ -2,7 +2,6 @@ Name:           lwp
 Version:        2.6
 Release:        18%{?dist}
 Summary:        C library for user-mode threading
-Group:          System Environment/Libraries
 License:        LGPLv2
 URL:            http://www.coda.cs.cmu.edu/
 Source0:        ftp://ftp.coda.cs.cmu.edu/pub/lwp/src/%{name}-%{version}.tar.gz
@@ -19,7 +18,6 @@ procedure call library).
 
 %package        devel
 Summary:        Development files for %{name}
-Group:          Development/Libraries
 Requires:       %{name}%{?_isa} = %{version}-%{release}
 
 %description    devel