Remove obsolete Group tag

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

openpgm.spec

@@ -3,7 +3,6 @@ Version:       5.2.122
 Release:       15%{?dist}
 Summary:       An implementation of the PGM reliable multicast protocol
 
-Group:         System Environment/Libraries
 # The license is LGPLv2.1
 License:       LGPLv2
 # New URL is https://github.com/steve-o/openpgm
@@ -24,7 +23,6 @@ Multicast (PGM) specification in RFC 3208.
 
 %package devel
 Summary:       Development files for openpgm
-Group:         Development/Libraries
 Requires:      %{name}%{?_isa} = %{version}-%{release}
 
 %description devel