Update CHANGELOG.md for 8.17.8

[ci skip]

CHANGELOG.md

@@ -1476,6 +1476,11 @@ entry.
 - Change development tanuki favicon colors to match logo color order.
 - API issues - support filtering by iids.
 
+## 8.17.8 (2017-08-09)
+
+- Remove hidden symlinks from project import files.
+- Disallow Git URLs that include a username or hostname beginning with a non-alphanumeric character.
+
 ## 8.17.7 (2017-07-19)
 
 - Renders 404 if given project is not readable by the user on Todos dashboard.