[instrument_manager] Fixing error in generate_tables_sql_and_testNames tool

[AlexandraLivadas]

The tools/generate_tables_sql_and_testNames.php script is causing an error when uploading a new instrument using the Instrument Manager module. Since the output string was being reset to empty within the for-loop, the "Create Table" statement was not properly generated.

Testing instructions

1. Go to the instrument manager module and try uploading the /test/instruments/test_all_fields.linst file
2. Check that there is a success message and that the project folder and database are correctly updated with the new instrument.

[laemtl]

Tests are failing :(
You gave a typo here:
$output = "": -> $output = "";

[driusan]

I'm assuming there's no related issue this should close?