[infer][PR] fix link to FAQ in issue template

Summary:
The current [link](http://fbinfer.com/support.html#troubleshooting) results in a 404 "page not found" error. Also updated to https since the website redirects to https anyway.
Pull Request resolved: https://github.com/facebook/infer/pull/1261

Reviewed By: ezgicicek

Differential Revision: D21763768

Pulled By: jvillard

fbshipit-source-id: 50a9bcf7a

ISSUE_TEMPLATE.md

@@ -1,4 +1,4 @@
-Please make sure your issue is not addressed in the [FAQ](http://fbinfer.com/support.html#troubleshooting).
+Please make sure your issue is not addressed in the [FAQ](https://fbinfer.com/docs/support#troubleshooting).
 
 Please include the following information:
 - [ ] The version of infer from `infer --version`.