NIFI-9312 Update Process Group context menu image in User Guide

Signed-off-by: Pierre Villard <pierre.villard.fr@gmail.com>

This closes #5468.
diff --git a/nifi-docs/src/main/asciidoc/images/nifi-process-group-menu.png b/nifi-docs/src/main/asciidoc/images/nifi-process-group-menu.png
index d8e0ea7..54edc73 100644
--- a/nifi-docs/src/main/asciidoc/images/nifi-process-group-menu.png
+++ b/nifi-docs/src/main/asciidoc/images/nifi-process-group-menu.png
Binary files differ