Change "orgCreationDisabled" -> "userOrgCreationDisabled" (langchain-ai#602)

## Overview
Changed in helm, need to match

## Type of change

**Type:** [Replace with: New documentation page / Update existing
documentation / Fix typo/bug/link/formatting / Remove outdated content /
Other]

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## Checklist
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- [ ] I have read the [contributing guidelines](README.md)
- [ ] I have tested my changes locally using `docs dev`
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## Additional notes
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Author: romain-priour-lc

src/langsmith/self-host-user-management.mdx

@@ -62,18 +62,18 @@ By default, any user can create an organization in LangSmith. For self-hosted cu
 #### Configuration
 
 <Note>
-The `orgCreationDisabled` feature flag is set to `true` by default for organizations using [basic auth](/langsmith/self-host-basic-auth) or [SSO](/langsmith/self-host-sso).
+The `userOrgCreationDisabled` feature flag is set to `true` by default for organizations using [basic auth](/langsmith/self-host-basic-auth) or [SSO](/langsmith/self-host-sso).
 </Note>
 <CodeGroup>
 
 ```yaml Helm
 config:
-  orgCreationDisabled: true
+  userOrgCreationDisabled: true
 ```
 
 ```bash Docker
 # In your .env file
-ORG_CREATION_DISABLED="true"
+FF_ORG_CREATION_DISABLED="true"
 ```
 
 </CodeGroup>