added missing spinner in landscape statistics frag

res/layout-land/fragment_statistics.xml

@@ -24,6 +24,15 @@
             android:id="@+id/plot_parent_layout"
             android:layout_weight="0.9">
 
+            <ProgressBar
+                android:id="@+id/progressBar1"
+                style="?android:attr/progressBarStyleLarge"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_centerHorizontal="true"
+                android:layout_centerVertical="true"
+                android:visibility="gone"/>
+
             <!-- TITLE LAYOUT -->
             <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                 android:orientation="vertical"