Check whether glibtoolize is available in addition to libtoolize

macOS doesn't have libtoolize and GNU libtool only installs glibtoolize.

Signed-off-by: Joerg Mayer <jmayer@loplof.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

autogen.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
 
+$(type glibtoolize >/dev/null 2>&1) && LIBTOOLIZE=${LIBTOOLIZE:-glibtoolize}
 aclocal -I m4 && \
 ${LIBTOOLIZE:-libtoolize} --automake --force && \
 autoheader --force &&