gdcm: Update to 3.2.5

[Dave-Allured]

Description

• Update gdcm 3.2.2 --> 3.2.5.
• Remove obsolete c_str patch. Was fixed upstream.
• Tentative build fix for 10.10, 10.11. Blacklist older clang versions.

Type(s)

Tested on

CI only.

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@MarcusCalhoun-Lopez for port gdcm.