Bump debhelper dependency to >= 10, since that's what is used in debian/compat.

Changes-By: lintian-brush
Fixes: lintian: package-lacks-versioned-build-depends-on-debhelper
See-also: https://lintian.debian.org/tags/package-lacks-versioned-build-depends-on-debhelper.html

debian/control

@@ -2,7 +2,7 @@ Source: spamdb
 Section: admin
 Priority: extra
 Maintainer: ale <ale@incal.net>
-Build-Depends: debhelper (>= 9),
+Build-Depends: debhelper (>= 10~),
                dh-golang,
                golang-any (>= 1.14)
 Standards-Version: 3.9.6