Fixes an incompatibility with Libtool 2+.

Rebased on FreeSOLID-2.1.2.

Originally retrieved from Fedora (see:
https://src.fedoraproject.org/rpms/FreeSOLID/raw/rawhide/f/FreeSOLID-2.1.1-configure.patch).

Upstream-status: https://sourceforge.net/p/freesolid/patches/10/

--- a/configure.in	2024-10-28 10:54:46.642783784 +0900
+++ b/configure.in	2024-10-28 10:55:47.558771350 +0900
@@ -1,8 +1,8 @@
 dnl Process this file with autoconf to produce a configure script.
-AC_INIT(sample/sample.cpp)
+AC_INIT
 AC_CONFIG_MACRO_DIR([m4])
 
-AC_CANONICAL_SYSTEM
+AC_CANONICAL_TARGET
 PACKAGE=FreeSOLID
 VERSION=2.1.1
 FREESOLID_CURRENT=2
@@ -15,15 +14,15 @@
 
 AM_INIT_AUTOMAKE($PACKAGE, $VERSION)
 
-AM_CONFIG_HEADER(include/config.h)
+AC_CONFIG_HEADERS([include/config.h])
 
 dnl Checks for programs.
-AC_LIBTOOL_WIN32_DLL
 AC_PROG_CXX
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_INSTALL
 AC_PROG_LIBTOOL
+LT_INIT([win32-dll])
 
 CPPFLAGS="$CPPFLAGS -I../include -I./include -I. -I../libbroad -I../libmoto"
 AC_SUBST(CPPFLAGS)