error occured when i build angular module with loopback sdk

[gazzua]

What type of issue are you creating?

• [x] Bug
• [x] Enhancement
• [ ] Question

What version of this module are you using?

• [ ] 2.0.10 (Stable)
• [ ] 2.1.0-rc.n (2.1 Release Candidate n)
• [x] Other

Write other if any: 2.2.7

Please add a description for your issue:

i have an error when i build angular module include loopback sdk

Cannot call a namespace ('io')
Error: Cannot call a namespace ('io')
    at error (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:199:15)
    at Module.error (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:17170:9)
    at CallExpression.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:14725:30)
    at ReturnStatement.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13499:23)
    at BlockStatement$$1.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13495:31)
    at FunctionExpression.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13499:23)
    at MethodDefinition.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13499:23)
    at ClassBody.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13495:31)
    at ClassDeclaration$$1.NodeBase.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:13499:23)
    at ExportNamedDeclaration.bind (/home/kms/dev/m2u/admin-web/web/node_modules/rollup/dist/rollup.js:15060:30)

this is error occur from import * as io from 'socket.io-client'; in socket.browser.ts

and this error not appear when i change socket.browser.ts

import * as io from 'socket.io-client';

to

import * as ioImported from 'socket.io-client';
const io = ioImported;

If you think this is ok please merge this commit