adjust eslint 'prefer-destructuring' rule
adjust eslint 'prefer-destructuring' rule

This rule was configured to allow for conditional assignment
without forcing destructuring which requires the use of wrapping
parentheses and a lonely semicolon. This style was roundly
rejected after discussion.

Example:

  let foo
  ;({foo} = bar)

Change-Id: I3cfe1be2ac18ce88481367830e2eb30effbc3340
Reviewed-on: https://gerrit.instructure.com/140916
Reviewed-by: Clay Diffrient <9dff2e5c98626d20d2848250c411e8009465bb87@instructure.com>
Tested-by: Jenkins
Product-Review: Jeremy Neander <20252aad5efdc666f083d82ab63ed0f9f72a043e@instructure.com>
QA-Review: Jeremy Neander <20252aad5efdc666f083d82ab63ed0f9f72a043e@instructure.com>

sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms