[gtk] docs: Fix typo in the migration guide

[Emmanuele Bassi <ebassi src gnome org>]

commit f559de112bad1cdc02ccc099662547d718cad2bc
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Apr 3 11:27:18 2019 +0100

    docs: Fix typo in the migration guide

 docs/reference/gtk/migrating-3to4.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/docs/reference/gtk/migrating-3to4.xml b/docs/reference/gtk/migrating-3to4.xml
index 8a6d09c5d3..e0087db3a3 100644
--- a/docs/reference/gtk/migrating-3to4.xml
+++ b/docs/reference/gtk/migrating-3to4.xml
@@ -672,7 +672,7 @@
         Since GtkScrolledWindow can deal with widgets that do not implement
         the GtkScrollable interface by automatically wrapping them into a
         GtkViewport, GtkLayout is redundant, and has been removed in favor
-        of the existing GtkFixed containter widget.
+        of the existing GtkFixed container widget.
       </para>
     </section>
   </section>