fixed a segv if version file download fails.
fixed a segv if version file download fails.

benzhi888/renminbi,effectsToCause/vericoin,effectsToCause/vericoin,effectsToCause/vericoin,benzhi888/renminbi,effectsToCause/vericoin,benzhi888/renminbi,effectsToCause/vericoin,benzhi888/renminbi,benzhi888/renminbi