Fixed crash when you select the settings manu with a very crude hack - needs doing properly really!

app/src/main/java/uk/org/openseizuredetector/PrefActivity.java

@@ -156,6 +156,17 @@ public class PrefActivity extends PreferenceActivity implements SharedPreference
         }
     }
 
+    /**
+     * FIXME - this just returns true so it is the same as for older versions of Android.
+     * We should really check that the fragmentName is one of the fragments defined below.
+     * @param fragmentName
+     * @return
+     */
+    @Override
+    protected boolean isValidFragment(String fragmentName) {
+        return true;
+    }
+
         /**
          * This fragment shows the preferences for the first header.
          */