Description of problem:
If a field error shows, such as the "username can only have characters x", if a word runs over the width of the field it will break in the middle. It looks bad.

Version-Release number of selected component (if applicable):
3.4.0-snapshot

How reproducible:
Moderate, always

Steps to Reproduce:
1. Click register
2. Inspect the username element and change the accompanying warning element text to
"lowercase letters, numbers and underscores (regex ...)"

Actual results:
The word "underscores" is wrapped in the middle

Expected results:
"underscores" should be placed on the next line, not broken.

Additional info:
Found when fixing a warning with a weak description.