fetch_packages: Fix FreeBSD platform checking.

We want every FreeBSD to mach the condition statement not only the
FreeBSD-10.
fetch_packages: Add 'autoreconf' ivocation for the Thrift package.

Patches for the Thrift modify its Makefile.am and the configure script
has to be regenerated. If autoreconf is not relaunch it causes errors
if the versions of aclocal, autoconf or automake differs on the build host
differ from those used while creating the package.