[libgsf] Docs: fix build

[Morten Welinder <mortenw src gnome org>]

commit fac625a7d03d3231fd8b129c8b1e343621bd611f
Author: Morten Welinder <terra gnome org>
Date:   Mon Mar 23 18:07:35 2020 -0400

    Docs: fix build
    
    Something is borked with the doc build.  This seems to fix it, but it
    is not clear why.

 doc/gsf-sections.txt | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/doc/gsf-sections.txt b/doc/gsf-sections.txt
index ba1a795..e9942fa 100644
--- a/doc/gsf-sections.txt
+++ b/doc/gsf-sections.txt
@@ -792,6 +792,10 @@ gsf_property_settings_collect
 gsf_property_settings_collect_valist
 gsf_property_settings_free
 
+<SUBSECTION Private>
+GSF_DEPRECATED_FOR
+</SECTION>
+
 <SECTION>
 <FILE>metadata</FILE>
 GsfDocMetaData