Webhook Input Field in Escalation Policy not Opening When Slack is Disabled

[mastercactapus]

Describe the Bug:
When trying to add a webhook on the Edit Step dialog in the Escalation Policy while Slack is disabled, the input field is not displayed at all and fails to expand as expected. This issue seems to be persistent across all browsers.

Steps to Reproduce:

1. Go to the 'Edit Step' dialog in the 'Escalation Policy'
2. Click on 'Add Webhook' while Slack is disabled
3. Observe that the input field does not display or expand to allow user input.

Expected Behavior:
Upon clicking 'Add Webhook', the input field should expand to allow user to input data even when Slack is disabled.

Observed Behavior:
The input field does not display or expand when 'Add Webhook' is clicked with Slack disabled.

Application Version:
GoAlert version output:

Version:   v0.31.0-45-g0cd7d3265
GitCommit: 0cd7d326507399c5a3ccbb1d7082e23ce7e41c34 (clean)
BuildDate: 2023-09-06T09:37:15-05:00
GoVersion: go1.21.0 (gc)
Platform:  linux/amd64
Migration: alert-feedback-id (#237)

Additional Context:
This issue was found while trying to reproduce a user-reported bug. It appears to affect all browsers.