Update README.md (#615)

Update README.md:  update the second "[good first issue]" to "[good pro issue]"

README.md

@@ -57,7 +57,7 @@ Hippo-4J 获得了一些宝贵的荣誉，肯定了 Hippo-4J 作为一款开源
 
 Hippo-4J 获得的成就属于每一位对 Hippo-4J 做出过贡献的成员，感谢各位的贡献。
 
-如果屏幕前的同学有意提交 Hippo-4J，请参考 [good first issue](https://github.com/opengoofy/hippo4j/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) 或者 [good first issue](https://github.com/opengoofy/hippo4j/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+pro+issue%22) 任务列表。
+如果屏幕前的同学有意提交 Hippo-4J，请参考 [good first issue](https://github.com/opengoofy/hippo4j/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) 或者 [good pro issue](https://github.com/opengoofy/hippo4j/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+pro+issue%22) 任务列表。
 
 <a href="https://github.com/opengoofy/hippo4j/graphs/contributors"><img src="https://opencollective.com/hippo4j/contributors.svg?width=890&button=false" /></a>