Show accessible device classes in combobox

This is a tiny bug and was fixed because @haufs and @boukhele need it to add their run configuration devices to a project

Author: wegerk

src/pythonGui/karabo_gui/project/dialog/device_handle.py

@@ -114,7 +114,7 @@ def visitor(node):
             for class_id, visibility in zip(attrs.get('deviceClasses', []),
                                             attrs.get('visibilities', [])):
                 # Only show accessible plugins depending on global access level
-                if AccessLevel(visibility) >= krb_globals.GLOBAL_ACCESS_LEVEL:
+                if AccessLevel(visibility) > krb_globals.GLOBAL_ACCESS_LEVEL:
                     continue
                 available_plugins.add(class_id)