DEVELOPERS: update email address

Signed-off-by: Doug Kehn <rdkehn@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -670,7 +670,7 @@ N:	Dominik Faessler <faessler@was.ch>
 F:	package/logsurfer/
 F:	package/python-id3/
 
-N:	Doug Kehn <rdkehn@yahoo.com>
+N:	Doug Kehn <rdkehn@gmail.com>
 F:	package/nss-pam-ldapd/
 F:	package/sp-oops-extract/
 F:	package/unscd/