[libhandy] swipeable: Include config.h

[Adrien Plazas <aplazas src gnome org>]

commit 69ca38f5320a5858f8f97e4e46a3bcacba1946f4
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Jul 28 16:38:35 2020 +0500

    swipeable: Include config.h
    
    HDY_AVAILABLE_IN_ALL macro in the following commits will depend on this.
    
    Signed-off-by: Alexander Mikhaylenko <alexm gnome org>

 src/hdy-swipeable.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/hdy-swipeable.c b/src/hdy-swipeable.c
index 54fc7e18..6be17130 100644
--- a/src/hdy-swipeable.c
+++ b/src/hdy-swipeable.c
@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: LGPL-2.1+
  */
 
+#include "config.h"
+
 #include "hdy-swipeable.h"
 
 /**