Changed "some-host" to "localhost" in example/config.docker

[baziorek]

Description

In one of our config file we had database default address: "some-postgres". Those sample files are for Iroha's beginners to run Iroha as fast as possible. Telling them to change sample configs to run Iroha IMO is not helping them. Also it is making our life harder, because many times somebody was asking about "I'm doing as in instruction and it is not working".

What is more - we have few config files in example/ directory:

ls config*
config.docker  config.postgres.sample  config.sample  config-win.sample

in all of config files the host for DB is localhost, only in one of them (which I'm changing now) it is some-postgres.

• iroha/example/config-win.sample

  Line 5 in 88de1c6

  "pg_opt" : "host=localhost port=5432 user=postgres password=mysecretpassword",

• iroha/example/config.postgres.sample

  Line 7 in 88de1c6

  "host": "localhost",

• config.sample - this is using RocksDB instead of Postgres

Linked issue

Closes #{issue_number}

Benefits

1. Easier for Iroha's beginners to run example
2. Less work for us with explaining to them where to change config files
3. Consequence in config files

Checklist

• I've read CONTRIBUTING.md
• I've used the standard signed-off commit format (or will squash just before merging)
• All applicable CI checks pass (or I promised to make them pass later)
• (optional) I've written unit tests for the code changes
• I replied to all comments after code review, marking all implemented changes with thumbs up

[6r1d]

That looks reasonable to me, thank you for the detailed description.