[gtranslator] Add missing tooltip to Sort-by button

[Daniel Mustieles García <dmustieles src gnome org>]

commit d8923610adc5f9dac9a38ab8ca19a082312fa559
Author: Daniel Mustieles <daniel mustieles gmail com>
Date:   Fri Jan 17 14:20:05 2020 +0100

    Add missing tooltip to Sort-by button

 src/gtr-notebook.ui | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/gtr-notebook.ui b/src/gtr-notebook.ui
index 769ec3c0..3a2b5de3 100644
--- a/src/gtr-notebook.ui
+++ b/src/gtr-notebook.ui
@@ -534,6 +534,7 @@
         <property name="can_focus">True</property>
         <property name="receives_default">True</property>
         <property name="popover">order_menu_popover</property>
+        <property name="tooltip_text" translatable="yes">Sort messages by</property>
         <child>
           <object class="GtkImage">
             <property name="visible">True</property>