Assembly: Fix objects in group would not have the dragger appear when selected.

src/Mod/Assembly/App/AssemblyObject.cpp

@@ -2291,6 +2291,10 @@ App::DocumentObject* AssemblyObject::getMovingPartFromRef(App::DocumentObject* o
             continue;
         }
 
+        if (obj->isDerivedFrom<App::DocumentObjectGroup>()) {
+            continue;  // we ignore groups.
+        }
+
         return obj;
     }
 

src/Mod/Assembly/UtilsAssembly.py

@@ -1107,6 +1107,9 @@ def getMovingPart(assembly, ref):
         if not obj:
             continue
 
+        if obj.TypeId == "App::DocumentObjectGroup":
+            continue  # we ignore groups.
+
         return obj
 
     return None