Update en.json
Update en.json

Refs QO-896
Closes FOO-3063
flag=none

The JSON generator for I18n translations was fixed
to include explicit objects for the various language
plurals, which forced a change in the fallback English
translation JSON. This change should be committed.

Test plan:
* none

Change-Id: I78e751348a843d348c1418f2f5c560153a7e8062
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/299289
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Jacob Burroughs <8ecea6e385af5cf9f53123f5ca17fb5fd6a6d4b2@instructure.com>
QA-Review: Charley Kline <05950d7e90ba5e3da323378368c22b3ffaaf6647@instructure.com>
Product-Review: Charley Kline <05950d7e90ba5e3da323378368c22b3ffaaf6647@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms