fix: Startup script does not always perform migrations (#2246)

## Context

This PR is a fix for
#1945 (comment)

## Description

Lago startup script is relying on the `rails db:migrate:primary` to
perform the migration at startup.

Since in some situation, only one database is configured in the
`database.yml` file, the command is failing with the following error:
```
Unrecognized command "db:migrate:primary" (Rails::Command::UnrecognizedCommandError)
Did you mean?  db:migrate:up
```

This PR fixes this by using `rails db:migrate` instead when only one
database is present.

config/database.yml

@@ -9,6 +9,7 @@ development:
  password: changeme
  database: lago
  port: 5432
+ schema_search_path: "public"
  events:
  <<: *default
  host: db
@@ -73,6 +74,7 @@ production:
  url: <%= ENV['DATABASE_URL'] %>
  pool: <%= ENV.fetch('DATABASE_POOL', 10) %>
  prepared_statements: <%= ENV.fetch('DATABASE_PREPARED_STATEMENTS', true) %>
+ schema_search_path: <%= ENV.fetch('POSTGRES_SCHEMA', 'public') %>
  events:
  <<: *default
  url: <%= ENV['DATABASE_URL'] %>

scripts/start.sh

@@ -6,11 +6,13 @@ then
 fi
 
 rm -f ./tmp/pids/server.pid
-bundle exec rails db:migrate:primary
 
 if [ -v LAGO_CLICKHOUSE_ENABLED ] && [ "$LAGO_CLICKHOUSE_ENABLED" == "true" ]
 then
+ bundle exec rails db:migrate:primary
  bundle exec rake db:migrate:clickhouse
+else
+ bundle exec rails db:migrate
 fi
 
 bundle exec rails signup:seed_organization