Ignore diff returning 1 when theres a difference.

sql/GNUmakefile

@@ -17,17 +17,16 @@
 all: db-create db-fill sitevars
 
 db-create:
-	@rm -f ./.tmp-db-create.sql
+	@rm -f ./.tmp-db-create.sql ./.tmp-create-diff
 	@mysqldump -d tbdb > ./.tmp-db-create.sql
-	@diff ./database-create.sql ./.tmp-db-create.sql > ./.tmp-create-diff
+	@-diff ./database-create.sql ./.tmp-db-create.sql > ./.tmp-create-diff
 	@if test -s ./.tmp-create-diff; \
 	then \
 		cat ./.tmp-create-diff; \
 		echo "NOTE: Don't forget to update db-migrate.txt!"; \
 		mv ./.tmp-db-create.sql ./database-create.sql; \
 	fi
-	@rm -f ./.tmp-create-diff
-	@rm -f ./.tmp-db-create.sql
+	@rm -f ./.tmp-create-diff ./.tmp-db-create.sql
 
 db-fill:
 	@/usr/testbed/sbin/wap /usr/testbed/sbin/export_tables \