message: Fix test context silent crash
diff: import { settings } from '../../settings';
  import { ENV } from '@pixi/constants';
  -let context;
  +const unknownContext = {};
  +let context = unknownContext;
  /**
  * returns a little WebGL context to use for program inspection.
  @@ -12,7 +13,7 @@ let context;
  */
  export default function getTestContext()
  {
  - if (context !== undefined)
  + if (context === unknownContext)
  {
  const canvas = document.createElement('canvas');
  