Fix xquery check-format-users test on OpenBSD

check-format-users test doesn't work on OpenBSD as the diff command uses -B flag. That flag is not supported by OpenBSD diff command.

Here's an diff to fix the test by modifying the sed command a bit:

Index: gnu/xquery/testsuite/Makefile.am
--- gnu/xquery/testsuite/Makefile.am.orig
+++ gnu/xquery/testsuite/Makefile.am
@@ -80,8 +80,8 @@ check-xsltest1:
 
 check-format-users:
        $(KAWA) --xslt $(srcdir)/format-users.xsl $(srcdir)/users.xml \
-         |sed 's/^ *//'>tmp-format-users.html
-       @if diff -b -B $(srcdir)/exp-format-users.html tmp-format-users.html; then echo '#  format-users test passes'; else echo FAIL format-users test; fi
+         |sed 's/^ *//; /^\s*$$/d' >tmp-format-users.html
+       @if diff -b $(srcdir)/exp-format-users.html tmp-format-users.html; then echo '#  format-users test passes'; else echo FAIL format-users test; fi
 
 ./Mod1/mod1.class: mod1.xql
        $(CLASSPATH_ENV) $(KAWA) --module-static -d ../../.. -C $<