refactor: 兼容url-loader limit只能数字和字符串
refactor: 兼容url-loader limit只能数字和字符串

https://github.com/webpack-contrib/url-loader/blob/master/CHANGELOG.md#062-2017-10-04

kidney/guido,zuzucheFE/guido,kidney/static-build,kidney/guido,kidney/static-build