Exclude E_USER_DEPRECATED from error handler mask

[ksucherek]

Problem

ErrorHandler::register() used the mask E_ALL & ~E_DEPRECATED, which only excludes E_DEPRECATED (8192 — PHP engine deprecations). E_USER_DEPRECATED (16384) is a separate bit emitted by userland code via trigger_error($msg, E_USER_DEPRECATED).

Because E_USER_DEPRECATED fell through the mask, handleError() received it and threw an ErrorException, turning a deprecation notice from third-party libraries (e.g. symfony/deprecation-contracts, used by microsoft/azure-storage-common) into a fatal HTTP 500 error.

Fix

Added & ~E_USER_DEPRECATED to the error handler mask in ErrorHandler::register().

// before
set_error_handler(..., E_ALL & ~E_DEPRECATED);

// after
set_error_handler(..., E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED);