Remove lowenna (aka jhowardmsft) from maintainters

Signed-off-by: John Howard <github@lowenna.com>

MAINTAINERS

@@ -33,7 +33,6 @@
 			"johnstep",
 			"justincormack",
 			"kolyshkin",
-			"lowenna",
 			"mhbauer",
 			"runcom",
 			"stevvooe",