[BUGFIX] Fix broken svg flag

The vietnam svg flag is somewhat garbled. The external lib "region-flags"
isn't broken. It seems as if it was mutilated while adding it to the core
last time.

The broken svg icon is fixed by a re-run of `grunt svgmin` task.

Resolves: #79793
Releases: master, 7.6
Change-Id: Ic1337a1a7037fa95d739937571a1a4ed381e1dae
Reviewed-on: https://review.typo3.org/51662


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>