Disable compression by default in Dash 2

[jonmmease]

This PR changes the default value of the compress argument to the dash.Dash constructor from True to False.

Rational: Compression has a performance penalty, and is often handled at a higher level in the deployment stack (e.g. by NGINX or Dash Enterprise). This PR makes Flask-level compression opt-in rather than opt-out for Dash 2.

[alexcjohnson]

Also:

dash/dash/dash.py

Lines 199 to 200 in abfd9a8

	:param compress: Use gzip to compress files and data served by Flask.
	Default ``True``

Plus a changelog entry.

Then this is good to go 💃