Update README.rst - Githubissues

Summary

"+" trips bash and therefore the command fails. Putting the URL in quotation marks solves the issue.

[ ] If code changes were made then they have been tested.
- [ ] I have updated the documentation to reflect the changes.
[ ] This PR fixes an issue (please put issue # in summary).
[ ] This PR adds something new (e.g. new method or parameters).
[ ] This PR is a breaking change (e.g. methods or parameters removed/renamed)
[x] This PR is not a code change (e.g. documentation, README, ...)