Fix automake's warning, printed from build_configure

diff --git a/doc/docutils/Makefile.am b/doc/docutils/Makefile.am
index d222a9c25337733f187ab8a58bb04d8cbaf5ef47..7e0f8bfc849dec270c4770a7450d84e02984f609 100644 (file)
--- a/doc/docutils/Makefile.am
+++ b/doc/docutils/Makefile.am
@@ -30,7 +30,7 @@ RSTFILES = \
        overview.rst \
        docapi.rst
 
-EXTRA_DIST = images $(RSTFILES)
+EXTRA_DIST += images $(RSTFILES)
 
 SPHINXOPTS      =
 SOURCEDIR       = $(srcdir)