[Bug] ToM fails to start if no LDAP URI is setup

[pm-McFly]

Observations

ToM is crashing if not able to contact LDAP server

tom-1  | {
tom-1  |   e: TypeError:  is an invalid LDAP url (scope)
tom-1  |       at parse (/usr/src/app/packages/matrix-identity-server/node_modules/ldapjs/lib/url.js:15:13)
tom-1  |       at Array.map (<anonymous>)
tom-1  |       at new Client (/usr/src/app/packages/matrix-identity-server/node_modules/ldapjs/lib/client/client.js:113:52)
tom-1  |       at Object.createClient (/usr/src/app/packages/matrix-identity-server/node_modules/ldapjs/lib/client/index.js:17:12)
tom-1  |       at Ke.ldap (file:///usr/src/app/packages/matrix-identity-server/src/userdb/ldap.ts:16:29)
tom-1  |       at file:///usr/src/app/packages/matrix-identity-server/src/userdb/ldap.ts:44:12
tom-1  |       at new Promise (<anonymous>)
tom-1  |       at new Ke (file:///usr/src/app/packages/matrix-identity-server/src/userdb/ldap.ts:43:18)
tom-1  |       at new Be (file:///usr/src/app/packages/matrix-identity-server/src/userdb/index.ts:82:15)
tom-1  |       at new at (file:///usr/src/app/packages/matrix-identity-server/src/index.ts:162:37)
tom-1  | }
tom-1  | ERROR | 2025-02-19T12:55:56.361Z | Unable to initialize server | ERROR: TypeError:  is an invalid LDAP url (scope)

Expectations

ToM should run but indicates that the LDAP server is unavailable and provides a configuration helper for troubleshooting (at least the name of the config/env_vars to verify).