command file startup deletes values from config.json, ignores other commands
**Describe the bug**
Using a .cmd file with an option such as --threads-hint "80" will delete the option from the config.cfg file rather than set the option to the same.  Not all commands (such as user/url) seem to suffer this issue and will be ignored completely.  Also the ability to set options realtime in the config.json file will be lost while xmrig is running due to using a .cmd file to startup if you dont use --config=config.json variable.  Using --config=config.json variable will ignore .cmd line values in the .cmd file!

**To Reproduce**
Create a .cmd startup file with startup values and --config=config.json.

**Expected behavior**
.cmd variables should read from the .cmd startup file, and written to config.json if the variable autosave is true, not deleted from config.json!  Should still be able to set variables in config.json when launching from a .cmd file even without setting --config=config.json.

**Required data**
 - Log does not show anything
 - .cmd line: xmrig.exe --config=config.json --cpu-max-threads-hint 76 -a gr -o stratum+tcp://server -u wallet.name -p x -o stratum+tcp://server -u wallet.name -p x
 - OS:WIN10

**Additional context**
Add any other context about the problem here.
