DEVELOPERS: Merge my two entries
Merge my two entries in the DEVELOPERS file, because the mail address
<sven.haardiek@greenbone.net> is outdated.
Signed-off-by: Sven Haardiek <sven.haardiek@iotec-gmbh.de>
[Thomas: fix alphabetic ordering.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>