The package already uses the generic autoreconf fixup so the additional call
to autogen.sh is unneeded and might even introduce wrong versions of the
required autotools into the build.

Remove the unneeded Build/Configure override to simplify the Makefile.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

Signed-off-by: Ted Hess <thess@kitschensync.net>