Remove obsolete Group tag

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

utf8cpp.spec

@@ -6,7 +6,6 @@ Version:    2.3.4
 Release:    11%{?dist}
 Summary:    A simple, portable and lightweight library for handling UTF-8 encoded strings
 
-Group:      Development/Libraries
 License:    Boost
 URL:        http://utfcpp.sourceforge.net/
 Source0:    http://downloads.sourceforge.net/utfcpp/utf8_v2_3_4.zip
@@ -25,7 +24,6 @@ This project currently only contains header files, which can be found in the
 
 %package    devel
 Summary:    Header files for %{name}
-Group:      Development/Libraries
 BuildArch:  noarch
 Provides:   %{name}-static = %{version}-%{release}