Issue Description

We have recently been migrating Rails 5.2 apps from sentry-raven to sentry-ruby. We have 2 services that are being migrated, one that is on using sentry-raven 4.x (v4.8 to be exact, using Faraday). And another that we tried to upgrade to sentry-ruby v5.0.2. In the app using v4.8, we were able to use the steps in the (https://docs.sentry.io/platforms/ruby/migration/#renamedrelocated) to rename the proxy configuration option, and pass it a URL string as follows:

config.proxy #=> config.transport.proxy
# Example: config.transport.proxy = "http://myproxy.example.com:port"

However, doing the same when moving to v5.x throws an error when a proxy string is provided. This caused a production deployment issue for us because we only use a proxy in our production environment, and were not able to test for this in our development/testing environments.

Reproduction Steps

1. Configure Sentry Ruby using v5+, setting the transport.proxy option to a URL string based on the migration guide from sentry-raven.

Sentry.init do |config|
 config.transport.proxy = "http://myproxy.example.com:port"
 ...
end

2. Force triggering of an exception in a Rails controller method, such as Sentry.capture_exception(StandardError.new('This is an exception'))

Expected Behavior

One of the following

1. The Sentry Ruby HTTPTransport class should be able to handle the proxy as a URL string, and seamlessly convert the parse the URL string, OR
2. Sentry documentation should be updated, including the migration guide, to indicate the configuration value for config.transport.proxy should be a hash, and a string is NOT acceptable.

Actual Behavior

A no implicit conversion of Symbol into Integer exception is thrown when the proxy is set as a string instead of a hash. See the HTTPTransport class here. Therefore, events are not sent to Sentry.

See log

2022-04-01T15:20:58Z Sending envelope [event] 081d827b4aca47ecb25328d611027179 to Sentry
2022-04-01T15:20:58Z Event sending failed: no implicit conversion of Symbol into Integer
2022-04-01T15:20:58Z exception happened in background worker: String does not have #dig method
2022-04-01T15:20:58Z Sending envelope [transaction] 7193c21c36534fda8e4030d4e9a2dbd9 to Sentry
2022-04-01T15:20:58Z Transaction sending failed: no implicit conversion of Symbol into Integer
2022-04-01T15:20:58Z Unreported Transaction: V1::XXXXXController#create
2022-04-01T15:20:58Z exception happened in background worker: no implicit conversion of Symbol into Integer

Ruby Version

2.6.6

SDK Version

5+

Integration and Its Version

Rails/Sidekiq

Sentry Config

Sentry.init do |config|
  config.transport.proxy = "http://myproxy.example.com:port"
  ...
end