Update LXQt build dependencies.

debian/changelog

@@ -2,6 +2,7 @@ pavucontrol-qt (0.15.0-0ubuntu1) UNRELEASED; urgency=medium
 
   * New upstream release.
     - Update upstream signing key.
+    - Update LXQt build dependencies.
   * Update Standards-version to 4.5.0, no changes needed.
 
  -- Simon Quigley <tsimonq2@ubuntu.com>  Thu, 30 Apr 2020 23:54:59 -0500

debian/control

@@ -9,7 +9,7 @@ Build-Depends: debhelper-compat (= 12),
                libpulse-dev,
                libqt5svg5-dev,
                libqt5x11extras5-dev,
-               lxqt-build-tools (>= 0.6.0~),
+               lxqt-build-tools (>= 0.7.0),
                xdg-user-dirs
 Standards-Version: 4.5.0
 Vcs-Browser: https://phab.lubuntu.me/source/pavucontrol-qt/