TypeError "c.join is not a function" on outgoing integrations page

Description:

Opening the Integrations -> Outgoing tab leads to an empty page with the following error in the console:

/node_modules/react-dom/cjs/react-dom.production.min.js:217 TypeError: c.join is not a function
    at S (/client/admin/integrations/IntegrationsTable.js:1)
    at oh (/node_modules/react-dom/cjs/react-dom.production.min.js:161)
    at Rj (/node_modules/react-dom/cjs/react-dom.production.min.js:269)
    at Qj (/node_modules/react-dom/cjs/react-dom.production.min.js:254)
    at Kj (/node_modules/react-dom/cjs/react-dom.production.min.js:254)
    at yj (/node_modules/react-dom/cjs/react-dom.production.min.js:247)
    at eval (/node_modules/react-dom/cjs/react-dom.production.min.js:131)
    at exports.unstable_runWithPriority (/node_modules/scheduler/cjs/scheduler.production.min.js:27)
    at cg (/node_modules/react-dom/cjs/react-dom.production.min.js:130)
    at fg (/node_modules/react-dom/cjs/react-dom.production.min.js:131)

Steps to reproduce:

1. Go to the Admin area
2. Click on Integrations
3. Click on Outgoing

Expected behavior:

The list of outgoing integrations to show

Actual behavior:

An empty page with the above error in the browser console

Server Setup Information:

• Version of Rocket.Chat Server: 3.7.1
• Operating System: Ubuntu 18.04
• Deployment Method: docker rocketchat/rocket.chat:3.7.1
• Number of Running Instances: 1
• DB Replicaset Oplog: Enabled
• NodeJS Version: v12.18.4
• MongoDB Version: 3.6.20

Client Setup Information

• Desktop App or Browser Version: Safari 14.0.1 / Chrome 87.0.4280.66
• Operating System: macOS 10.14

Start with client/admin/integrations/IntegrationsTable.js, identified in the console stack trace, and reproduce the issue by opening Admin > Integrations > Outgoing. Trace the value causing c.join to fail, then verify that the outgoing integrations list renders without a console error.