Update reviewnotes plugin to latest revision

* ExportReviewNotes: Print an error message when failing to open project

Change-Id: Ic847861edc322246d35561b3e946477cb0af3396
diff --git a/plugins/reviewnotes b/plugins/reviewnotes
index 4d1a7b6..b5c6f81 160000
--- a/plugins/reviewnotes
+++ b/plugins/reviewnotes
@@ -1 +1 @@
-Subproject commit 4d1a7b61034d52859cc7349af41d1068e954556d
+Subproject commit b5c6f81d979e78fbd734d946b18270ec8319eaf6