Fix (en-us)download.md 2.7.2 Link failure (#527)

Fix (en-us)download.md 2.7.2 Link failure
diff --git a/blog/en-us/download.md b/blog/en-us/download.md
index b2094f4..e149a6f 100644
--- a/blog/en-us/download.md
+++ b/blog/en-us/download.md
@@ -36,9 +36,9 @@
 
 ### 2.7.2 (2019-06-06)
 
-* [source](https://archive.apache.org/dist/incubator/dubbo/2.7.2/apache-dubbo-incubating-2.7.2-src.zip) |
-[asc](https://archive.apache.org/dist/incubator/dubbo/2.7.2/apache-dubbo-incubating-2.7.2-src.zip.asc) |
-[sha512](https://archive.apache.org/dist/incubator/dubbo/2.7.2/apache-dubbo-incubating-2.7.2-src.zip.sha512)
+* [source](https://archive.apache.org/dist/dubbo/2.7.2/apache-dubbo-2.7.2-src.zip) |
+[asc](https://archive.apache.org/dist/dubbo/2.7.2/apache-dubbo-2.7.2-src.zip.asc) |
+[sha512](https://archive.apache.org/dist/dubbo/2.7.2/apache-dubbo-2.7.2-src.zip.sha512)
 
 ### 2.7.1 (2019-03-26)