Null-check call result rather than function itself

From the comment, it seems like this was supposed check for chords, rather than checking for the availability of `isChord`.

Signed-off-by: Andrew Casey <andrew.casey@microsoft.com>
Signed-off-by: Paul Maréchal <paul.marechal@ericsson.com>

examples/api-tests/src/monaco-api.spec.js

@@ -66,8 +66,7 @@ describe('Monaco API', async function () {
             }, {
                 label: 'Ctrl+Shift+Alt+K',
                 ariaLabel: 'Ctrl+Shift+Alt+K',
-                // eslint-disable-next-line no-null/no-null
-                electronAccelerator: null,
+                electronAccelerator: 'Ctrl+Shift+Alt+K',
                 userSettingsLabel: 'ctrl+shift+alt+K',
                 WYSIWYG: true,
                 chord: false,

packages/monaco/src/browser/monaco-resolved-keybinding.ts

@@ -49,7 +49,7 @@ export class MonacoResolvedKeybinding extends monaco.keybindings.ResolvedKeybind
     }
 
     public getElectronAccelerator(): string | null {
-        if (this.isChord) {
+        if (this.isChord()) {
             // Electron cannot handle chords
             // eslint-disable-next-line no-null/no-null
             return null;