Fix: missing schema param in inferred id run test

[marcomoscasgr]

During a log_publisher test, the connection to the tracking DB happens when the npg_tracking schema file is available on disk under the proper directory. If not present on disk the test passes skipping the connection. To avoid unexpected connections from this particular test when the file exists,npg_tracking_schema property should be set to undef.

[kjsanger]

Please add a comment in the test code alongside this so that it is clear why setting an undef argument has side-effects on a database (!!) Otherwise, someone may just remove it later.

[mgcam]

Please add a comment in the test code alongside this so that it is clear why setting an undef argument has side-effects on a database (!!) Otherwise, someone may just remove it later.

Good point. This test relies on the ability of the parent class to infer id_run. One might say that this test can be dropped since it does not test any code in the loader itself. id_run is retrieved either from a database run record or from the {r,R}unParameters.xml file in this order. Since the test did not provide a database handle, it tried to retrieve db credentials from $HOME/.npg and connect to whatever database is defined there. If that fails, it falls back to the {r,R}unParameters.xml route. In CI no test database was provided, so the fallback was successfully executed. If the user has credentials for the prod database in $HOME/.npg, a connection to the database is made. The fact that the tests connects to a database came to light when the database in question was a test database (listed as live), which refused connection, resulting in test failure with a fatal error. Setting the database handle to undef signals to the code that it should not try the database route.