Die with an error when configure fails (bug #3524).

client.mk

@@ -230,7 +230,9 @@ $(OBJDIR)/Makefile $(OBJDIR)/config.status $(OBJDIR)/config.cache: $(TOPSRCDIR)/
 	@echo ../configure
 	@cd $(OBJDIR) && \
 	  $(TOPSRCDIR)/configure $(CONFIG_FLAGS) \
-	  || echo Fix above errors and then restart with \"$(MAKE) -f client.mk build\"
+	  || echo "*** Fix above errors and then restart with\
+             \"$(MAKE) -f client.mk build\"" \
+          && exit 1
 
 ifdef CONFIG_STATUS
 $(OBJDIR)/config/autoconf.mk: $(TOPSRCDIR)/config/autoconf.mk.in