[Backport 2.2-develop] Fix label to avoid wrapping poorly,now break by word

[enriquei4]

Description

Backport to 2.2 of PR: " Fix: field labels wrapping poorly #11727 "
Some long labels break by letter, that was a UX problem to some users and confusiing. I've edited a styless-old.less to fix it.

Fixed Issues (if relevant)

Admin: field labels wrapping poorly #7099

Manual testing scenarios

1. Go to any page that has long input field labels, such as when adding a new product attribute (also depends of your resolution)
2. Now the labels break by word instead by letter.

BEFORE:

NOW:

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)