`/?useUnifiedTopology=true` should be in db_url!

[TinosNitso]

Line 37 of config.ts can be set to url: process.env.db_url ? process.env.db_url : 'mongodb://127.0.0.1:27017/?useUnifiedTopology=true',

Update: now (passed block# 727k) I'm trying equivalent of: url: process.env.db_url ? process.env.db_url : 'mongodb://127.0.0.1:27017/?useNewUrlParser=true&useUnifiedTopology=true&connectTimeoutMS=3600000', i.e. my db_url is mongodb://tinos.ml:27017/?useNewUrlParser=true&useUnifiedTopology=true&connectTimeoutMS=3600000. connectTimeout of 1 hr could work, but there's another timeout which occurred when I was asleep.

Without useUnifiedTopology=true I keep getting warning:

[INFO] gRPC: getBlockchainInfo
(node:2224) [MONGODB DRIVER] Warning: Current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
(Use `node --trace-warnings ...` to show where the warning was created)

As of block 726303 in my syncing process I've been getting lots of unexpected MongoDB timeouts & I'm hoping this solves the problem, but maybe not. I might have to pursue another update. Update: I still got another timeout, but now I'm trying mongodb://tinos.ml:27017/?useUnifiedTopology=true&connectTimeoutMS=3000000 Default connectTimeoutMS is only 10000, however I suspect 10 seconds isn't long enough. 360000 would've been a more elegant choice, to match the socketTimeoutMS default.

I'm aware db.ts line 22 already specifies useUnifiedTopology, which is why it took me so long to figure out the url!

Today I'm trying WSL2 for the 1st time, so I've learned to use nano, or else it's a lot more effort to set up VcXsrv & GUI. WSL1 maybe not as fast for some reason, & I've used KDiskMark to verify WSL2 is faster (SSD speed) than Hyper-V (which itself is much faster than VirtualBox). In WSL2 it's 172.29.160.1, or in my case tinos.ml, instead of 127.0.0.1 (it took me ages to realize mongod.exe needs to bind to a different IP, e.g. by restarting, & Windows Firewall is problematic too). Btw I still like VBox for testing, but not doing all the work.

All these WSL technicalities are relevant because the fountainhead-core module doesn't work in Windows due to a ./ cmd error.