MAINTAINERS: Stylize GunnarM Discord UserName

Change-Id: I9e229b4aef5170350978c174edc5b96cb1435282
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index e393c29..76a5a55 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -53,4 +53,4 @@
 M:  Patrick Williams <patrick@stwcx.xyz> <stwcx!>
 R:  Adriana Kobylak <anoo@us.ibm.com> <anoo!>
 R:  Andrew Jeffery <andrew@aj.id.au> <amboar!>
-R:  Gunnar Mills <gmills@linux.vnet.ibm.com> <gunnarm!>
+R:  Gunnar Mills <gmills@linux.vnet.ibm.com> <GunnarM!>