Less wrapping of network errors

[deivid-rodriguez]

I don't think it's useful to wrap network errors like this, but I might be missing something. I believe they tend to hide errors from the users. If something in particular should be better worded, I believe the builtin exception should be changed instead.

What was the end-user or developer problem that led to this PR?

I tried the new output after #4061 by disconnecting from the internet and running bundle install on an application. The results are:

Fetching source index from https://rubygems.org/

Retrying fetcher due to error (2/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <no such name (https://rubygems.org/specs.4.8.gz)>

Retrying fetcher due to error (3/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <no such name (https://rubygems.org/specs.4.8.gz)>

Retrying fetcher due to error (4/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <no such name (https://rubygems.org/specs.4.8.gz)>

Could not fetch specs from https://rubygems.org/ due to underlying error <no such name (https://rubygems.org/specs.4.8.gz)>

I think the message could be more informative including the underlying network error class, for example.

What is your fix for the problem, implemented in this PR?

Stop wrapping dns errors with a custom special exception to get a more wordy message. With this PR:

Fetching source index from https://rubygems.org/

Retrying fetcher due to error (2/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <SocketError: Failed to open TCP connection to rubygems.org:443 (getaddrinfo: Name or service not known) (https://rubygems.org/specs.4.8.gz)>

Retrying fetcher due to error (3/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <SocketError: Failed to open TCP connection to rubygems.org:443 (getaddrinfo: Name or service not known) (https://rubygems.org/specs.4.8.gz)>

Retrying fetcher due to error (4/4): Bundler::HTTPError Could not fetch specs from https://rubygems.org/ due to underlying error <SocketError: Failed to open TCP connection to rubygems.org:443 (getaddrinfo: Name or service not known) (https://rubygems.org/specs.4.8.gz)>

Could not fetch specs from https://rubygems.org/ due to underlying error <SocketError: Failed to open TCP connection to rubygems.org:443 (getaddrinfo: Name or service not known) (https://rubygems.org/specs.4.8.gz)>

Make sure he following tasks are checked

• Describe the problem / feature
• Write tests for features and bug fixes
• Write code to solve the problem
• Make sure you follow the current code style and write meaningful commit messages without tags

[bronzdoc]

Looks good, would you add some tests for this?

[deivid-rodriguez]

Almost 4 months later, I added some tests 😝.