[libxslt] Don't try to install index.sgml

[Nick Wellnhofer <nwellnhof src gnome org>]

commit ca31bcc695fca43185c8161a24c1b3df4d9b8f14
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Fri Dec 2 17:27:11 2016 +0100

    Don't try to install index.sgml
    
    This file is long gone.

 doc/Makefile.am |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/doc/Makefile.am b/doc/Makefile.am
index a69995a..ce657b6 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -314,7 +314,6 @@ install-data-local:
        $(MKDIR_P) $(DESTDIR)$(HTML_DIR)/html
        -$(INSTALL) -m 0644 $(srcdir)/html/*.html $(DESTDIR)$(HTML_DIR)/html
        -$(INSTALL) -m 0644 $(srcdir)/html/*.png $(DESTDIR)$(HTML_DIR)/html
-       -$(INSTALL) -m 0644 $(srcdir)/html/index.sgml $(DESTDIR)$(HTML_DIR)/html
        $(MKDIR_P) $(DESTDIR)$(HTML_DIR)/EXSLT
        -$(INSTALL) -m 0644 $(srcdir)/EXSLT/*.html $(DESTDIR)$(HTML_DIR)/EXSLT
        $(MKDIR_P) $(DESTDIR)$(HTML_DIR)/tutorial