Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1328935
Description of problem:
Operating system description length accepts more than 255 characters

Version-Release number of selected component (if applicable):
satellite-6.2.0-8.2.beta.el7sat.noarch

How reproducible:
Always

Steps to Reproduce:
1.Create an operating system with description of length 256 characters
2.
3.

Actual results:
Operating system created with no errors

Expected results:
Until last build, we allowed os description length upto a maximum of 255 characters only, now its broken.

Additional info: