DEVELOPERS: update e-mail for Frank Vanbever

Signed-off-by: Frank Vanbever <frank.vanbever@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 416213be39c6adb860a9d3e85f0a634139c27cac)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

DEVELOPERS

@@ -1027,7 +1027,7 @@ F:	package/ucl/
 F:	package/upx/
 F:	package/zxing-cpp/
 
-N:	Frank Vanbever <frank.vanbever@essensium.com>
+N:	Frank Vanbever <frank.vanbever@mind.be>
 F: 	package/elixir/
 F:	package/libmodsecurity/
 F:	package/nginx-modsecurity/