[gtk] gdkrgba: Add a missing apostrophe in a doc comment

[Daniel Boles <dboles src gnome org>]

commit a15080c640d7516316ed29924d638bd6dcffc0c2
Author: Daniel Boles <dboles src gmail com>
Date:   Mon Mar 19 15:13:04 2018 +0000

    gdkrgba: Add a missing apostrophe in a doc comment

 gdk/gdkrgba.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/gdkrgba.c b/gdk/gdkrgba.c
index 833396b180..de1c594337 100644
--- a/gdk/gdkrgba.c
+++ b/gdk/gdkrgba.c
@@ -55,7 +55,7 @@ G_DEFINE_BOXED_TYPE (GdkRGBA, gdk_rgba,
  *   1.0 for opaque
  *
  * A #GdkRGBA is used to represent a (possibly translucent)
- * color, in a way that is compatible with cairos notion of color.
+ * color, in a way that is compatible with cairo’s notion of color.
  */
 
 /**