`--threads` option does not take precedence over automatically-located config file
**Describe the bug**
I believe that configuration options should be used in this order:
1. If a CLI argument is specified, use it.
2. If a configuration file is specified as a CLI argument via the `--config` argument, use the parameters in that configuration file.
3. Otherwise, use the parameters found in the configuration file found at a default search path (e.g., `.config/xmrig.json`).

Currently, the number of threads configuration parameter (and maybe other parameters too) appear to be fetched in the order 3, 1, 2.

**To Reproduce**
1. Create a configuration file at `~/.config/xmrig.json`. Do not specify threads in this file.
2. Run `xmrig --threads 1`

**Expected behavior**
xmrig should run with only one thread

**Actual behavior**
xmrig runs with as many threads as the system has cores/cpus.

**Required data**
- Linux
- xmrig v6.21.0

**Additional context**
Running with `xmrig --config .config/xmrig.json --threads 1` works properly (and also still works properly independent of the argument order). The issue appears to exclusively be when an auto-located configuration is used.