Fix wrapping of change description text.
Fix wrapping of change description text.

When moving to lessCSS for the stylesheets, the rule for the <pre> in
the change description box was nested incorrectly, resulting in the
text overflowing the box. This rule is now fixed.

davidt/reviewboard,reviewboard/reviewboard,chipx86/reviewboard,1tush/reviewboard,brennie/reviewboard,brennie/reviewboard,sgallagher/reviewboard,custode/reviewboard,beol/reviewboard,sgallagher/reviewboard,1tush/reviewboard,1tush/reviewboard,custode/reviewboard,bkochendorfer/reviewboard,sgallagher/reviewboard,custode/reviewboard,reviewboard/reviewboard,davidt/reviewboard,1tush/reviewboard,beol/reviewboard,KnowNo/reviewboard,bkochendorfer/reviewboard,reviewboard/reviewboard,bkochendorfer/reviewboard,custode/reviewboard,KnowNo/reviewboard,KnowNo/reviewboard,KnowNo/reviewboard,1tush/reviewboard,bkochendorfer/reviewboard,brennie/reviewboard,1tush/reviewboard,davidt/reviewboard,beol/reviewboard,beol/reviewboard,1tush/reviewboard,sgallagher/reviewboard,1tush/reviewboard,chipx86/reviewboard,reviewboard/reviewboard,chipx86/reviewboard,1tush/reviewboard,brennie/reviewboard,davidt/reviewboard,chipx86/reviewboard