Add autoconf-archive to dependencies

We use AX_EXT in ./configure for checking CPU features anyway, so it's
better to add it as explicit dependency.

Related: OS#1923
Change-Id: I7ba48e1df4ede8b477574da3faa15fd02e15c69b
diff --git a/debian/control b/debian/control
index d016afa..151aa92 100644
--- a/debian/control
+++ b/debian/control
@@ -4,6 +4,7 @@
 Maintainer: Ivan Klyuchnikov <ivan.kluchnikov@fairwaves.ru>
 Build-Depends: debhelper (>= 9),
                autotools-dev,
+               autoconf-archive,
                libdbd-sqlite3,
                libsqlite3-dev,
                pkg-config,