Fix #6821 changelog entry

[CyberShadow]

This is a partial revert of 0d40de4. This commit introduced a number of problems:

1. The title was two lines, which did not conform to the syntax as described in README.md, and caused the generated changelog to be misformed (see http://dlang.org/changelog/2.075.0_pre.html)

2. There was trailing whitespace on the second line, causing dlang.org's test target to fail

3. Subjectively, I'm having trouble understanding the new wording. The old wording was much more concise, and if it was factually incorrect, I don't see how.

CC @UplinkCoder @wilzbach

[wilzbach]

Thanks!

[wilzbach]

This commit introduced a number of problems:
The title was two lines, which did not conform to the syntax as described in README.md, and caused the generated changelog to be misformed (see http://dlang.org/changelog/2.075.0_pre.html)
There was trailing whitespace on the second line, causing dlang.org's test target to fail

That's why I'm setting it directly to auto-deploy merge.
@UplinkCoder I hardly doubt that you have anything against this, but if so, we can always do this, once the test target is green again and we have enabled an enforcement check for its passing it ;-)

[UplinkCoder]

It's fine.
Unfortunately I am not used to ddoc :)