gnu: xfce: Add xfce4-pulseaudio-plugin.

* gnu/packages/xfce.scm (xfce)[propagated-inputs]: Add xfce4-pulseaudio-plugin.

gnu/packages/xfce.scm

@@ -666,15 +666,17 @@ (define-public xfce
        ("thunar-volman"        ,thunar-volman)
        ("tumlber"              ,tumbler)
        ("xfce4-appfinder"      ,xfce4-appfinder)
-       ("xfce4-battery-plugin" ,xfce4-battery-plugin)
-       ("xfce4-clipman-plugin" ,xfce4-clipman-plugin)
        ("xfce4-panel"          ,xfce4-panel)
        ("xfce4-session"        ,xfce4-session)
        ("xfce4-settings"       ,xfce4-settings)
        ("xfce4-terminal"       ,xfce4-terminal)
        ("xfconf"               ,xfconf)
        ("xfdesktop"            ,xfdesktop)
-       ("xfwm4"                ,xfwm4)))
+       ("xfwm4"                ,xfwm4)
+       ;; Panel plugins.
+       ("xfce4-battery-plugin"    ,xfce4-battery-plugin)
+       ("xfce4-clipman-plugin"    ,xfce4-clipman-plugin)
+       ("xfce4-pulseaudio-plugin" ,xfce4-pulseaudio-plugin)))
     (home-page "http://www.xfce.org/")
     (synopsis "Desktop environment (meta-package)")
     (description