[gxml] subproject: add src dir to be used as subproject

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit f25b8cc3fc1b64c61955d4160f5cd8748752859a
Author: Daniel Espinosa <esodan gmail com>
Date:   Tue Jul 2 18:43:40 2019 -0500

    subproject: add src dir to be used as subproject

 gxml/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gxml/meson.build b/gxml/meson.build
index 46c50b1..2327fa9 100644
--- a/gxml/meson.build
+++ b/gxml/meson.build
@@ -189,7 +189,7 @@ custom_target('typelib',
 endif
 endif
 
-
+libxml_build_dir = meson.current_build_dir ()
 libgxml_dep = declare_dependency(include_directories : inc_rooth,
   link_with : libgxml,
   dependencies: libgxml_deps,