Fixed alignment of buttons in note forms

## What does this MR do?

Due to a CSS change on some buttons, the alignment of the save button on the note form went off. Also, it made no sense to have `.btn-grouped` as the button wasn't in a group.

## Screenshots (if relevant)

![Screen_Shot_2016-06-17_at_11.43.33](/uploads/5d9037a48ff6179fc906bdf0c6d5ff47/Screen_Shot_2016-06-17_at_11.43.33.png)

![Screen_Shot_2016-06-17_at_11.43.43](/uploads/8b130a25e8f73e79578d38f5f7aff4fb/Screen_Shot_2016-06-17_at_11.43.43.png)


See merge request !4740