[Applet] Correctly hide separator when there are no connected devices

Leftover from d34ae3f0.

This code generally needs a refactor to be more declarative, which will
be done later.

src/applet/package/contents/ui/FullRepresentation.qml

@@ -14,6 +14,8 @@ import org.kde.plasma.components 2.0 as PlasmaComponents // for Highlight
 import org.kde.plasma.components 3.0 as PlasmaComponents3
 import org.kde.plasma.private.bluetooth 1.0 as PlasmaBt
 
+import "logic.js" as Logic
+
 PlasmaComponents3.Page {
 
     Action {
@@ -77,7 +79,7 @@ PlasmaComponents3.Page {
                 // group because it's unnecessary; all we want to do here is
                 // separate the connected devices from the available ones
                 section.delegate: Loader {
-                    active: section != "Connected"
+                    active: section != "Connected" && Logic.conectedDevicesCount() > 0
                     sourceComponent: Item {
                         width: listView.width
                         height: PlasmaCore.Units.gridUnit

src/applet/package/contents/ui/logic.js

@@ -68,3 +68,16 @@ function icon()
     }
     return "preferences-system-bluetooth";
 }
+
+function conectedDevicesCount() {
+  var connectedDevices = [];
+
+  for (var i = 0; i < btManager.devices.length; ++i) {
+    var device = btManager.devices[i];
+    if (device.connected) {
+      connectedDevices.push(device);
+    }
+  }
+
+  return connectedDevices.length
+}