windows-msys: fix missing makedepends on libbacktrace

windows-msys/PKGBUILD-libbacktrace

@@ -9,7 +9,7 @@ arch=('any')
 url="https://github.com/ianlancetaylor/libbacktrace"
 license=('BSD')
 depends=("${MINGW_PACKAGE_PREFIX}-gcc-libs")
-makedepends=('git')
+makedepends=('git' 'autoconf')
 source=("https://git.sr.ht/~alextee/libbacktrace/archive/${pkgver}.tar.gz")
 sha256sums=('SKIP')