MAINTAINERS: update email address

The old one still works for now, but will not work indefinitely.
Signed-off-by: NJosh Durgin <jdurgin@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

MAINTAINERS

@@ -1169,7 +1169,7 @@ S: Supported
 F: block/vmdk.c
 
 RBD
-M: Josh Durgin <josh.durgin@inktank.com>
+M: Josh Durgin <jdurgin@redhat.com>
 M: Jeff Cody <jcody@redhat.com>
 L: qemu-block@nongnu.org
 S: Supported