MTU fix - set docker-compose MTU to 1440

[shaal]

The Problem/Issue/Bug

Since yesterday (April 15) running composer through ddev in Gitpod, resulted in errors.
This seems to be related to Fastly endpoints, and wrong MTU value in docker-compose - gitpod-io/gitpod#9354

A permanent solution is being worked on - gitpod-io/gitpod#9356

How this PR Solves The Problem

Set the correct MTU level (1440) manually

Manual Testing Instructions

In terminal type ddev ssh
Run 10 times -

• curl https://www.drupal.org

Related Issue Link(s)

Release/Deployment notes

[shaal]

Gitpod created a custom docker-compose that includes MTU 1440.
ddev is set to use its own docker-compose binary by default /home/gitpod/.ddev/bin/docker-compose

I tried setting ddev's global config use_docker_compose_from_path: true, but it resulted with many errors.

I'll merge this PR until a better solution is available through Gitpod / ddev.

[shaal]

Summary -
Temporary fix for network issues when running composer inside ddev container (in Gitpod)

Since Gitpod removed slirp4netns as part of performance improvements,
MTU value should be aligned to the one in gitpod.io

Gitpod fixed it for docker - gitpod-io/gitpod#9356
and for docker-compose - gitpod-samples/template-docker-compose#4

ddev doesn't use Gitpod's custom docker-compose binary. Instead, ddev uses
its own docker-compose binary at /home/gitpod/.ddev/bin/docker-compose
ddev issue [WIP] - ddev/ddev#3766

Align the MTU value to the one that is set in Gitpod (1440)