[gtk-doc] docs: make yelp usage conditional in manual

[Stefan Kost <stefkost src gnome org>]

commit 5a06d25131f4148613b3c151f7ad5ab5f39e281c
Author: Sebastian Rasmussen <sebras hotmail com>
Date:   Sun Dec 1 14:15:42 2013 +0100

    docs: make yelp usage conditional in manual
    
    The help/manual directory will be recursed into (so make dist can
    include everything) even if not in SUBDIRS in help/Makefile.am. Because
    of this help/manual/Makefile.am is always used to generate the
    help/manual/Makefile. And so if help/manual/Makefile.am includes
    unconditional yelp usage then help/manual/Makefile will also include
    yelp usage, even if yelp is not available.
    
    Fixes https://bugzilla.gnome.org/show_bug.cgi?id=719644

 help/manual/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/help/manual/Makefile.am b/help/manual/Makefile.am
index c56a1ed..fb5b498 100644
--- a/help/manual/Makefile.am
+++ b/help/manual/Makefile.am
@@ -1,4 +1,6 @@
+if HAVE_YELP_TOOLS
 @YELP_HELP_RULES@
+endif
 
 HELP_ID = gtk-doc-manual