cosmetic: don't log about missing SQLite log cb

SQLite3 seems to be commonly compiled without log callback support. It is then
misleading to see a seeming error message about this on each osmo-hlr startup.

Avoid the impression that we would miss out on important logging: query
sqlit3_compileoption_get() whether SQLITE_CONFIG_SQLLOG is enabled. Try to
register the callback only if present, if not, say so on DEBUG log.

See https://sqlite.org/compile.html "SQLITE_ENABLE_SQLLOG"

Change-Id: I78d75dc351eb587b0a022f82f147e9a31c0324c5
1 file changed