Fix NameError in intelmqdump when loading global settings fails

[cristianchiriac]

Fixes #2702.

Bug

In intelmq/bin/intelmqdump.py, main() tries to load global settings to determine the log level:

try:
    defaults = utils.get_global_settings()
except Exception:
    log_level = DEFAULT_LOGGING_LEVEL

If get_global_settings() raises (incomplete setup, e.g. a dev install before running intelmqsetup, or a deleted runtime config), defaults is never assigned — but the very next block unconditionally calls defaults.get(...), so instead of failing with the real, informative exception the tool crashes with a confusing NameError: name 'defaults' is not defined, exactly as described in the issue.

Fix

Set defaults = {} in the except block, matching the fix suggested in the issue.

Note: main() calls get_global_settings() again, unguarded, further down (to enumerate bots and their dump locations). If the setup is genuinely and persistently broken, that second call still legitimately fails — this fix doesn't make the tool run without any config, it just replaces the confusing internal NameError with the real underlying exception (or lets the tool proceed normally, if the first failure was transient).

Test plan

• Added test_incomplete_setup_does_not_raise_nameerror, mocking get_global_settings to raise and asserting specifically that main() doesn't raise NameError — any other exception from later in main() (the genuinely-broken-setup case above) is expected and not what the test guards against.
• Verified the crash and fix in isolation (intelmqdump.py imports fcntl and is Unix-only, and I don't have a Linux environment set up to run the full suite here) — reproduced the exact NameError from the unpatched try/except logic, confirmed it's gone after the one-line fix.