[CT-NG:patch 05/19] Force autoreconf for mpfr

In some exotic case the autoreconf step of mpfr is not executed (correctly)
leaving an incorrect version number for libtool in the configure script.

After extracting the sources files, force autoreconf to be executed.

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>

syntax: glob

# Generated files

Makefile

ct-ng

docs/ct-ng.1

docs/ct-ng.1.gz

paths.mk

scripts/crosstool-NG.sh

scripts/saveSample.sh

scripts/showTuple.sh

# Temporaries

.*.swp

log.*

# Working files

kconfig/conf

kconfig/mconf

kconfig/**.o

kconfig/**.dep

config.gen/

.config

.config.old

targets/