minor design changes

ubl-settings-video.glade

@@ -694,11 +694,13 @@ translated and supported by community.</property>
   <object class="GtkImage" id="image13">
     <property name="visible">True</property>
     <property name="can-focus">False</property>
+    <property name="tooltip-text" translatable="yes">Switch</property>
     <property name="icon-name">system-shutdown-symbolic</property>
   </object>
   <object class="GtkImage" id="image14">
     <property name="visible">True</property>
     <property name="can-focus">False</property>
+    <property name="tooltip-text" translatable="yes">Delete</property>
     <property name="icon-name">user-trash-symbolic</property>
   </object>
   <object class="GtkImage" id="image15">
@@ -713,6 +715,7 @@ translated and supported by community.</property>
   <object class="GtkImage" id="image3">
     <property name="visible">True</property>
     <property name="can-focus">False</property>
+    <property name="tooltip-text" translatable="yes">Configure</property>
     <property name="icon-name">open-menu-symbolic</property>
     <style>
       <class name="thin"/>
@@ -833,6 +836,7 @@ translated and supported by community.</property>
             <property name="visible">True</property>
             <property name="can-focus">True</property>
             <property name="receives-default">True</property>
+            <property name="tooltip-text" translatable="yes">Add</property>
             <property name="image">image15</property>
             <style>
               <class name="thin"/>