Remade position text on slides.

ubinstall-gtk-slider.glade

@@ -69,7 +69,9 @@
               <object class="GtkLabel" id="TextLabel">
                 <property name="visible">True</property>
                 <property name="can-focus">False</property>
+                <property name="xpad">6</property>
                 <property name="use-markup">True</property>
+                <property name="justify">fill</property>
                 <property name="wrap">True</property>
                 <property name="xalign">0</property>
               </object>