coolwsd.xml defaults do not match built-in defaults

[xzfc]

Describe the Bug

The comment in COOLWSD.cpp states that defaults from coolwsd.xml and built-in defaults from the coolwsd C++ sources should be the same. However, they are not. Consequently, when coolwsd is started with an empty coolwsd.xml, the factual configuration would not be the same as if it was started with the default coolwsd.xml.

This cause problems for systems that generate the coolwsd.xml config file on its own (e.g. Nix). We can't generate coolwsd.xml from scratch with just a few user-specified options, we have to patch the default coolwsd.xml instead. This is inconvenient.

Incomplete list of mismatched options:

Option	coolwsd.xml	built-in
logging.level	@COOLWSD_LOGLEVEL@/warning	trace
num_prespawn_children	4	1
per_document.cleanup[@enable]	true	false
per_view.out_of_focus_timeout_secs	300	120 or 60
ssl.termination	false	true
ssl.cert_file_path	/etc/coolwsd/cert.pem	COOLWSD_CONFIGDIR "/cert.pem"/ /usr/local/etc/coolwsd/cert.pem
storage.ssl.as_scheme	true	false
And others

Steps to Reproduce

1. Create empty.xml with this contents: <config></config>.
2. First run: run coolwsd with the default coolwsd.xml.
3. Second run: run coolwsd --config-file=empty.xml.

Expected Behavior

Both runs should behave exactly the same.

Actual Behavior

They are not. Presumably, the most visible difference is the logging level (see the table above) and paths to SSL certs.

[timar]

wrt. storage.ssl.as_scheme there is a comment why it is so: wsd/wopi/StorageConnectionManager.cpp#L163