Update docs url

(cherry picked from commit b5ce0005)

common/xfpm-common.c

@@ -120,7 +120,7 @@ xfpm_about (gpointer data)
        "program-name", package,
        "translator-credits", _("translator-credits"),
        "version", PACKAGE_VERSION,
-       "website", "http://docs.xfce.org/xfce/xfce4-power-manager/1.4/start",
+       "website", "https://docs.xfce.org/xfce/xfce4-power-manager/start",
        "logo-icon-name", "org.xfce.powermanager",
        NULL);
 }

data/appdata/xfce4-power-manager.appdata.xml.in

@@ -34,7 +34,7 @@
 
   <url type="homepage">http://www.xfce.org/</url>
   <url type="bugtracker">https://gitlab.xfce.org/xfce/xfce4-power-manager</url>
-  <url type="help">http://docs.xfce.org/xfce/xfce4-power-manager/start</url>
+  <url type="help">https://docs.xfce.org/xfce/xfce4-power-manager/start</url>
 
   <update_contact>xfce4-dev@xfce.org</update_contact>
   <translation type="gettext">xfce4-power-manager</translation>

panel-plugins/power-manager-plugin/xfce/xfce-power-manager-plugin.c

@@ -72,10 +72,10 @@ power_manager_plugin_configure_response (GtkWidget    *dialog,
 
   if (response == GTK_RESPONSE_HELP)
   {
-    result = g_spawn_command_line_async ("exo-open --launch WebBrowser " "http://docs.xfce.org/xfce/xfce4-power-manager/1.6/start", NULL);
+    result = g_spawn_command_line_async ("exo-open --launch WebBrowser " "https://docs.xfce.org/xfce/xfce4-power-manager/start", NULL);
 
     if (G_UNLIKELY (result == FALSE))
-      g_warning (_("Unable to open the following url: %s"), "http://docs.xfce.org/xfce/xfce4-power-manager/1.6/start");
+      g_warning ("Unable to open the following url: %s", "https://docs.xfce.org/xfce/xfce4-power-manager/start");
   }
   else
   {