The logos have been changed to match the new CI,
but were cut out sloppily.

Exchange the most prominent logos with proper ones.

Fixes: #42850
Releases: 6.0, 4.7, 4.6, 4.5

Change-Id: Id5ac815b8c2b381bef89f9e152345fd29a822bf6
Reviewed-on: http://review.typo3.org/16391
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel