Uncaught TypeError: Cannot read property 'remove' of undefined

[Enter steps to reproduce:]

1. Press escape.

**Atom**: 1.41.0 x64
**Electron**: 4.2.7
**OS**: Mac OS X 10.14.6
**Thrown From**: [script](https://github.com/rgbkrk/atom-script) package 3.25.0

### Stack Trace

Uncaught TypeError: Cannot read property 'remove' of undefined

```
At /Users/mjstaw/.atom/packages/script/node_modules/atom-message-panel/lib/MessagePanelView.js:189

TypeError: Cannot read property 'remove' of undefined
at ScriptView.MessagePanelView.remove (/packages/script/node_modules/atom-message-panel/lib/MessagePanelView.js:189:30)
at ScriptView.detach (/packages/platformio-ide-terminal/node_modules/jquery/dist/jquery.js:5357:15)
at ScriptView.removePanel (/packages/script/lib/script-view.js:89:10)
at Object.closeScriptViewAndStopRunner (/packages/script/lib/script.js:161:21)
at HTMLElement.coreCancel (/packages/script/lib/script.js:92:33)
at CommandRegistry.handleCommandEvent (/Applications/Atom.app/Contents/Resources/app/static/:11:349392)
at KeymapManager.dispatchCommandEvent (/Applications/Atom.app/Contents/Resources/app/static/:11:1252536)
at KeymapManager.handleKeyboardEvent (/Applications/Atom.app/Contents/Resources/app/static/:11:1248670)
at WindowEventHandler.handleDocumentKeyEvent (/Applications/Atom.app/Contents/Resources/app/static/:11:284598)
```

### Commands

```
-0:20.9.0 editor:consolidate-selections (input.hidden-input)
-0:20.9.0 core:cancel (input.hidden-input)
-0:20.7.0 editor:consolidate-selections (input.hidden-input)
-0:20.7.0 core:cancel (input.hidden-input)
-0:20.6.0 editor:consolidate-selections (input.hidden-input)
-0:20.6.0 core:cancel (input.hidden-input)
-0:20.3.0 editor:consolidate-selections (input.hidden-input)
-0:20.3.0 core:cancel (input.hidden-input)
-0:20.1.0 editor:consolidate-selections (input.hidden-input)
-0:20.1.0 core:cancel (input.hidden-input)
-0:19.9.0 editor:consolidate-selections (input.hidden-input)
-0:19.9.0 core:cancel (input.hidden-input)
-0:19.7.0 editor:consolidate-selections (input.hidden-input)
-0:19.7.0 core:cancel (input.hidden-input)
-0:08.9.0 editor:consolidate-selections (input.hidden-input)
-0:08.9.0 core:cancel (input.hidden-input)
```

### Non-Core Packages

```
atom-runner 2.7.1
platformio-ide-terminal 2.10.0
script 3.25.0
```