docs(readme): fix rstcheck violation [skip ci]

https://travis-ci.org/github/myii/icinga2-formula/builds/731606737#L259

```
docs/README.rst:21: (ERROR/3) Content block expected for the "note" directive; none found.
```

Author: myii

docs/README.rst

@@ -18,8 +18,6 @@ A salt formula that installs and configures icinga2, currently on Debian and Ubu
 installation source can be easily added. Configuration via pillar currently for hosts and
 services only.
 
-.. note::
-
 Suggestions, pull-requests, bug reports and comments are welcome.
 
 .. contents:: **Table of Contents**