Check for utf8 local support before testing it.

Check for utf8 local support and if not found, do not attempt to run the
utf8 tests.  Suggested by djm@
diff --git a/Makefile.in b/Makefile.in
index 3990f55..e10f374 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -580,6 +580,7 @@
 	TEST_SSH_PUTTYGEN="puttygen"; \
 	TEST_SSH_CONCH="conch"; \
 	TEST_SSH_IPV6="@TEST_SSH_IPV6@" ; \
+	TEST_SSH_UTF8="@TEST_SSH_UTF8@" ; \
 	TEST_SSH_ECC="@TEST_SSH_ECC@" ; \
 	cd $(srcdir)/regress || exit $$?; \
 	$(MAKE) \
@@ -604,6 +605,7 @@
 		TEST_SSH_PUTTYGEN="$${TEST_SSH_PUTTYGEN}" \
 		TEST_SSH_CONCH="$${TEST_SSH_CONCH}" \
 		TEST_SSH_IPV6="$${TEST_SSH_IPV6}" \
+		TEST_SSH_UTF8="$${TEST_SSH_UTF8}" \
 		TEST_SSH_ECC="$${TEST_SSH_ECC}" \
 		TEST_SHELL="${TEST_SHELL}" \
 		EXEEXT="$(EXEEXT)" \