[libxslt] Require automake-1.16.3 or later

[Nick Wellnhofer <nwellnhof src gnome org>]

commit d980d6cb50813b81025cba71ec7127ac813bef8c
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Aug 29 15:41:37 2022 +0200

    Require automake-1.16.3 or later
    
    See https://gitlab.gnome.org/GNOME/libxml2/-/commit/df003c0aea767904c44de1bf420dc2a721347ad3

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index 9582b98f..a2406e6c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -67,7 +67,7 @@ AC_SUBST(LIBEXSLT_VERSION_INFO)
 AC_SUBST(LIBEXSLT_VERSION_NUMBER)
 AC_SUBST(LIBEXSLT_VERSION_EXTRA)
 
-AM_INIT_AUTOMAKE([1.15 foreign no-dist-gzip dist-xz])
+AM_INIT_AUTOMAKE([1.16.3 foreign no-dist-gzip dist-xz])
 AM_MAINTAINER_MODE([enable])
 AM_SILENT_RULES([yes])