[gtk+] build: Fix gtk_tools array expansion

[Emmanuele Bassi <ebassi src gnome org>]

commit 95beabe4d65f7facf5afd1339134d58f3668e74b
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Oct 20 11:22:45 2017 +0100

    build: Fix gtk_tools array expansion
    
    The gtk_tools variable is an array of arrays; adding a new element
    requires to maintain the same type, or we'll get a build failure when
    we try to extract the newly added element.

 gtk/meson.build |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/meson.build b/gtk/meson.build
index 23c15ea..da95435 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -1027,7 +1027,7 @@ gtk_tools = [
 ]
 
 if os_unix
-  gtk_tools += ['gtk4-launch', ['gtk-launch.c']]
+  gtk_tools += [['gtk4-launch', ['gtk-launch.c']]]
 endif
 
 foreach tool: gtk_tools