chore: Add comment on FF_DEBUG_NO_SSO_REDIRECT usage

.env.example

@@ -75,7 +75,7 @@ PAGERDUTY_ACCOUNT_EMAIL="[email protected]"
 PAGERDUTY_API_KEY="u+XXXXXXXXXXXXXXXX-X"
 PAGERDUTY_URL="https://api.pagerduty.com"
 
-## SSO settings (optional)
+## SSO settings
 
 OIDC_OP_DISCOVERY_DOCUMENT_URL=https://oauth.mycompany.local/auth/realms/realm/.well-known/openid-configuration
 OIDC_RP_CLIENT_ID=firefighter-incident
@@ -97,5 +97,6 @@ RAID_DEFAULT_JIRA_QRAFT_USER_ID="XXXXXXXX" #gitleaks:allow
 RAID_JIRA_PROJECT_KEY="T2"
 
 FF_SLACK_SKIP_CHECKS=true
-# Disable SSO redirect for local dev by setting to true. When SSO is disabled, go to /admin/ to login
+# Disable SSO redirect for local dev by setting to true but still need a valid URL in OIDC_OP_DISCOVERY_DOCUMENT_URL.
+# When SSO is disabled, go to /admin/ to login
 FF_DEBUG_NO_SSO_REDIRECT=false