Remove obsolete Group tag

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

gflags.spec

@@ -3,7 +3,6 @@ Version:        2.2.1
 Release:        1%{?dist}
 Summary:        Library for commandline flag processing
 
-Group:          Development/Tools
 License:        BSD
 URL:            https://gflags.github.io/gflags/
 Source0:        https://github.com/%{name}/%{name}/archive/v%{version}/%{name}-%{version}.tar.gz
@@ -20,7 +19,6 @@ they're used.
 
 %package devel
 Summary:        Development files for %{name}
-Group:          Development/Libraries
 
 Requires:       %{name}%{?_isa} = %{version}-%{release}