remove unnecessary double template, fixing gcc-8.1 compilation error, see https://groups.google.com/forum/#!topic/sage-devel/NgzlZknrizg
remove unnecessary double template, fixing gcc-8.1 compilation error, see https://groups.google.com/forum/#!topic/sage-devel/NgzlZknrizg

linbox-team/linbox,linbox-team/linbox,linbox-team/linbox,linbox-team/linbox,linbox-team/linbox