Fixed background color of contact adapter row to match themes

astrid/res/layout/contact_adapter_row.xml

@@ -4,7 +4,7 @@
     xmlns:astrid="http://schemas.android.com/apk/res/com.timsu.astrid"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
-    android:background="@android:drawable/list_selector_background"
+    android:background="?attr/asContentBackground"
     android:padding="4dip"
     android:paddingRight="6dip"
     android:orientation="horizontal">