Update autogen.sh

Author: div72

autogen.sh

@@ -1,15 +1,16 @@
 #!/bin/sh
-# Copyright (c) 2013-2016 The Bitcoin Core developers
+# Copyright (c) 2013-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+export LC_ALL=C
 set -e
-srcdir="$(dirname $0)"
+srcdir="$(dirname "$0")"
 cd "$srcdir"
-if [ -z ${LIBTOOLIZE} ] && GLIBTOOLIZE="`which glibtoolize 2>/dev/null`"; then
+if [ -z "${LIBTOOLIZE}" ] && GLIBTOOLIZE="$(command -v glibtoolize)"; then
   LIBTOOLIZE="${GLIBTOOLIZE}"
   export LIBTOOLIZE
 fi
-which autoreconf >/dev/null || \
+command -v autoreconf >/dev/null || \
   (echo "configuration failed, please install autoconf first" && exit 1)
 autoreconf --install --force --warnings=all