[libxslt] Suppress automake warning in tests/XSLTMark

[Nick Wellnhofer <nwellnhof src gnome org>]

commit d20f7ab817f6fd381dc63b958ab652f316ab6ec7
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Dec 7 11:26:38 2020 +0100

    Suppress automake warning in tests/XSLTMark
    
    The "html" target is overridden deliberately.

 tests/XSLTMark/Makefile.am | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/tests/XSLTMark/Makefile.am b/tests/XSLTMark/Makefile.am
index 250992c3..6932fef6 100644
--- a/tests/XSLTMark/Makefile.am
+++ b/tests/XSLTMark/Makefile.am
@@ -1,5 +1,6 @@
 ## Process this file with automake to produce Makefile.in
 
+AUTOMAKE_OPTIONS = -Wno-override
 EXTRA_DIST = \
   dbgen.pl \
   alphabetize.out alphabetize.ref alphabetize.xsl \