app/matrix: add q3k to OWNERS

(apparently these don't get inherited?)

Change-Id: Ie0052677585863da6dade8c184e25b8c15ddf42c
diff --git a/app/matrix/OWNERS b/app/matrix/OWNERS
index cf63283..789b750 100644
--- a/app/matrix/OWNERS
+++ b/app/matrix/OWNERS
@@ -1,3 +1,4 @@
 inherited: false
 owners:
   - informatic
+  - q3k