main/json-c: regen autoconf

fixxes error about missing autoheader

main/json-c/APKBUILD

 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=json-c
 pkgver=0.12
-pkgrel=0
+pkgrel=1
 pkgdesc="A JSON implementation in C"
 url="https://github.com/json-c/json-c/wiki"
 arch="all"
 license="MIT"
 depends=""
 depends_dev=""
-makedepends="$depends_dev"
+makedepends="$depends_dev autoconf automake libtool"
 install=""
 subpackages="$pkgname-dev"
 source="https://s3.amazonaws.com/${pkgname}_releases/releases/$pkgname-${pkgver}.tar.gz
@@ -24,6 +24,8 @@ prepare() {
 		*.patch) msg $i; patch -p1 -i "$srcdir"/$i || return 1;;
 		esac
 	done
+	libtoolize --force && aclocal && autoconf && autoheader \
+		&& automake --add-missing
 }
 
 build() {