Remove obsolete Group tag

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

cairomm.spec

@@ -9,7 +9,6 @@ Version:        1.12.0
 Release:        9%{?dist}
 URL:            http://www.cairographics.org
 License:        LGPLv2+
-Group:          System Environment/Libraries
 Source:         http://www.cairographics.org/releases/%{name}-%{version}.tar.gz
 BuildRequires:  gcc-c++
 BuildRequires:  cairo-devel >= %{cairo_version}
@@ -28,7 +27,6 @@ Standard Template Library where it makes sense.
 
 %package        devel
 Summary:        Headers for developing programs that will use %{name}
-Group:          Development/Libraries
 Requires:       %{name}%{?_isa} = %{version}-%{release}
 
 %description    devel
@@ -41,7 +39,6 @@ developing %{name} applications.
 
 %package        doc
 Summary:        Developer's documentation for the cairomm library
-Group:          Documentation
 BuildArch:      noarch
 Requires:       %{name} = %{version}-%{release}
 Requires:       libsigc++20-doc