[gtk-doc/wip/tintou/create-xml-before-use] cmake: copy the XML file before using it

[Corentin Noël <corentinnoel src gnome org>]

commit 7f96f7beb3d516be0524d8083f1e29b15b67565a
Author: Corentin Noël <corentin elementary io>
Date:   Fri Oct 5 15:11:50 2018 +0200

    cmake: copy the XML file before using it
    
    Otherwise, gtkdoc-mkdb doesn't find it and think that we are using Autotools and asks for 
gtkdocentities.ent.

 buildsystems/cmake/GtkDocConfig.cmake.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/buildsystems/cmake/GtkDocConfig.cmake.in b/buildsystems/cmake/GtkDocConfig.cmake.in
index 9d41696..94cfe52 100644
--- a/buildsystems/cmake/GtkDocConfig.cmake.in
+++ b/buildsystems/cmake/GtkDocConfig.cmake.in
@@ -253,13 +253,13 @@ function(gtk_doc_add_module _doc_prefix)
             ${_depends}
         ${_remove_xml_if_needed}
         COMMAND ${CMAKE_COMMAND} -E remove_directory ${_output_xml_dir}
+        ${_copy_xml_if_needed}
         COMMAND ${GTKDOC_MKDB_EXE}
             --module=${_doc_prefix}
             ${_source_dirs_opt}
             --source-suffixes=${_doc_source_suffixes}
             --output-format=xml
             --main-sgml-file=${_default_xml_file}
-        ${_copy_xml_if_needed}
         WORKING_DIRECTORY "${_output_dir}"
         VERBATIM)