Update ISSUE_TEMPLATE.md

.github/ISSUE_TEMPLATE.md

@@ -7,7 +7,8 @@
 > a lot has changed with Xcode 8 that is not backwards compatible.
 >
 > Xcode 8 Status: Only works with CocoaPods 1.1.0
-> Swift 3: You need to add a `swift_version` file, see the CHANGELOG
+> Swift 3: You need to add a `.swift-version` file, see the CHANGELOG
+> China: Use https://gems.ruby-china.org/ instead of https://gems.ruby-china.org/ for the RC see #5910
 
 * [ ] I've read and understood the [*CONTRIBUTING guidelines and have done my best effort to follow](https://github.com/CocoaPods/CocoaPods/blob/master/CONTRIBUTING.md).