Update build dependencies.

debian/changelog

@@ -2,6 +2,7 @@ lxqt-themes (0.13.0-0ubuntu1) UNRELEASED; urgency=medium
 
   * New upstream release.
   * Update Vcs-* and Maintainer to Lubuntu values.
+  * Update build dependencies.
 
  -- Simon Quigley <tsimonq2@ubuntu.com>  Tue, 22 May 2018 21:44:41 -0500
 

debian/control

@@ -5,7 +5,7 @@ Uploaders: Alf Gaida <agaida@siduction.org>,
            ChangZhuo Chen (陳昌倬) <czchen@debian.org>
 Section: x11
 Priority: optional
-Build-Depends: debhelper (>= 11~),
+Build-Depends: debhelper (>= 11),
                cmake,
                lxqt-build-tools
 Standards-Version: 4.1.4