[gnome-calendar] Mark missing strings for translation

[Piotr Drąg <piotrdrag src gnome org>]

commit 5410ae5ac67299871dc31ec6f2ab8ef5b822e874
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Thu Sep 28 13:18:07 2017 +0200

    Mark missing strings for translation
    
    Unfortunately, Glade suffers from
    https://bugzilla.gnome.org/show_bug.cgi?id=782753

 data/ui/source-dialog.ui |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/data/ui/source-dialog.ui b/data/ui/source-dialog.ui
index b98f0f5..de50ffe 100644
--- a/data/ui/source-dialog.ui
+++ b/data/ui/source-dialog.ui
@@ -742,7 +742,7 @@
     <child type="titlebar">
       <object class="GtkHeaderBar" id="headerbar">
         <property name="visible">True</property>
-        <property name="title">Calendar Settings</property>
+        <property name="title" translatable="yes">Calendar Settings</property>
         <property name="show_close_button">True</property>
         <child>
           <object class="GtkButton" id="back_button">
@@ -863,7 +863,7 @@
     <child type="titlebar">
       <object class="GtkHeaderBar" id="credentials_headerbar">
         <property name="visible">True</property>
-        <property name="title">Enter your credentials</property>
+        <property name="title" translatable="yes">Enter your credentials</property>
         <child>
           <object class="GtkButton" id="credentials_cancel_button">
             <property name="label" translatable="yes">Cancel</property>