flamingo: Pin to commit that does not break HTML-pages

Commit
https://github.com/pengutronix/flamingo/commit/0a498b95d2f8fcb5920cc0e5e9d5637e47704346


changes the HTML parsing behavior of flamingo.
Images are now handled by the core.
Thus the images are not taken from the /static folder.

This change pins flamingo to the commit prior to the above.
We should fix freifunk-bs.de (some time later)...

Signed-off-by: Chris Fiege <chris@tinyhost.de>

flamingo/REQUIREMENTS-deploy.txt

-git+git://github.com/pengutronix/flamingo@master#egg=flamingo
+git+git://github.com/pengutronix/flamingo@a4684c87d0d4859988a0eca5958b09671582d01b#egg=flamingo
 beautifulsoup4==4.5.3
 Pillow==4.3.0
 ipython==6

flamingo/REQUIREMENTS-full.txt

-git+git://github.com/pengutronix/flamingo@master#egg=flamingo[full]
+git+git://github.com/pengutronix/flamingo@a4684c87d0d4859988a0eca5958b09671582d01b#egg=flamingo[full]
 beautifulsoup4==4.5.3
 Pillow==4.3.0
 ipython==6