Add missing build dependencies.

debian/changelog

@@ -3,6 +3,7 @@ lxqt-config (0.13.0+git20181226-0ubuntu1) UNRELEASED; urgency=medium
   * New upstream Git snapshot.
     - Remove reverse-applicable patches.
     - Add a patch lowering the LXQt version required.
+    - Add missing build dependencies.
 
  -- Simon Quigley <tsimonq2@ubuntu.com>  Sun, 30 Dec 2018 16:39:06 -0600
 

debian/control

@@ -13,7 +13,9 @@ Build-Depends: debhelper (>= 11),
                libx11-dev,
                libxcursor-dev,
                libxfixes-dev,
+               libxi-dev,
                qtbase5-private-dev,
+               xserver-xorg-input-libinput-dev,
                zlib1g-dev
 Standards-Version: 4.1.5
 Vcs-Browser: https://phab.lubuntu.me/source/lxqt-config/