libfplll soname bump

I will soon build libfplll 5.3.0 in Rawhide, which entails an soname bump from libfplll.so.5 to libfplll.so.6, even though abipkgdiff reports no ABI changes. I will rebuild the dependent packages, gap-pkg-float and python-fpylll. Note that linbox and Macaulay2 also consume libfplll-static, but since there are no ABI changes, I'll leave them to their next updates or the mass rebuild, whichever comes first. -- Jerry James http://www.jamezone.org/