scan: fix progress bar position

vlc-android/res/layout/main.xml

@@ -7,13 +7,12 @@
     <org.videolan.vlc.widget.ContentLinearLayout
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"
-        android:layout_weight="1"
-        android:orientation="horizontal" >
+        android:orientation="vertical" >
 
         <FrameLayout
             android:id="@+id/fragment_placeholder"
             android:layout_width="fill_parent"
-            android:layout_height="wrap_content"
+            android:layout_height="0dp"
             android:layout_weight="1" />
 
         <RelativeLayout