R1:0ef08baf6452

Fix a PHP 8.1 deprecated use of strlen with a NULL argument

Summary:
This strlen() call was preventing a new Phorge instance to be deployed/configured.
Indeed, on a fresh instance, configuration's "base-uri" key may not be defined witch lead to a Runtime Exception.
Using strlen() to check string validity is deprecated since PHP 8.1, phorge adopts phutil_nonempty_string() as a replacement.

Note: this may highlight other absurd input values that might be worth correcting
instead of just ignoring. If…