Update CONTRIBUTING.md (#90)

Author: syleeeee

CONTRIBUTING.md

@@ -35,6 +35,6 @@ uploading a pull request.
 
 ## Contributor license agreement
 
-If you are sending a pull request and it's a non-trivial change beyond fixing
-typos, please make sure to sign the [ICLA (Individual Contributor License Agreement)](https://feedback.line.me/enquete/public/919-h9Yqmr1u).
-Please contact us if you need the CCLA (Corporate Contributor License Agreement).
+When you are sending a pull request and it's a non-trivial change beyond fixing typos, please make sure to sign
+[the ICLA (individual contributor license agreement)](https://cla-assistant.io/line/line-bot-sdk-nodejs). Please
+[contact us](mailto:dl_oss_dev@linecorp.com) if you need the CCLA (corporate contributor license agreement).