Switch to side-by-side view

--- a/src/qtgui/uiprefs.ui
+++ b/src/qtgui/uiprefs.ui
@@ -547,6 +547,20 @@
                                             </widget>
                                         </hbox>
                                     </widget>
+                                    <widget class="Line">
+                                        <property name="name">
+                                            <cstring>line3</cstring>
+                                        </property>
+                                        <property name="frameShape">
+                                            <enum>HLine</enum>
+                                        </property>
+                                        <property name="frameShadow">
+                                            <enum>Sunken</enum>
+                                        </property>
+                                        <property name="orientation">
+                                            <enum>Horizontal</enum>
+                                        </property>
+                                    </widget>
                                     <spacer>
                                         <property name="name">
                                             <cstring>spacer2</cstring>