web-ui settings: Fix a typo for the sans-serif preference key via font settings.
web-ui settings: Fix a typo for the sans-serif preference key via font settings.

BUG=none
TEST=Verify that the settings page loads w/o an exception.
Review URL: http://codereview.chromium.org/6708015

git-svn-id: http://src.chromium.org/svn/trunk/src@78607 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 944b73e4e92978477ede85d355b40c67491b4bd5
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser