ffmpeg: update to 3.2.4 [security]

[l2dy]

Description

(delete all below for minor changes)

Tested on

macOS 10.12.3
Xcode 8.2.1

Verification

Have you

• followed our Commit Message Guidelines?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL? (Please don't open a new Trac ticket if you are submitting a pull request.)
• checked your Portfile with port lint?
• tried a full install with sudo port -v install?
• tested basic functionality of all binary files? (delete if not applicable)

[mojca]

Did you check any of the dependent ports?

[l2dy]

No, I didn't. My Internet connection is horrible so I'm expecting the maintainers to test this change.

[l2dy]

@jeremyhu @dbevans
From https://www.ffmpeg.org/security.html:

3.2.4 fixes following vulnerabilities:
CVE-2017-5024, ed2572b9c8f885e2a4764d2e34604442a71899a1 / 2d453188c2303da641dafb048dc1806790526dfd
CVE-2017-5025, cf8e004a51b08c6e8ceaeebca85ab84c7ed0b4cf / fd30e4d57fe5841385f845440688505b88c0f4a9

[l2dy]

@ryandesign Please don't add merge commits like 2f8d7fd90a.

[ryandesign]

Why not?

[l2dy]

Because I'd prefer keeping my PRs clean.

[l2dy]

Fixed in 8b50768.