add BuildRequires: gcc-c++,gcc

Reference: https://fedoraproject.org/wiki/Changes/Remove_GCC_from_BuildRoot

jsoncpp.spec

@@ -12,6 +12,8 @@ License:        Public Domain or MIT
 URL:            https://github.com/open-source-parsers/%{name}
 Source0:        %{url}/archive/%{version}.tar.gz#/%{name}-%{version}.tar.gz
 
+BuildRequires:  gcc
+BuildRequires:  gcc-c++
 BuildRequires:  cmake >= 3.1
 BuildRequires:  python3-devel