BUG: registerCopy may fail for copy construct of regIOobject

- checkIn() was incorrectly conditional on the register state of the
  source object.

Partial patch from .org commit 6dc48b62d948

src/OpenFOAM/db/regIOobject/regIOobject.C

@@ -96,9 +96,12 @@ Foam::regIOobject::regIOobject(const regIOobject& rio, bool registerCopy)
     eventNo_(db().getEvent()),
     isPtr_(nullptr)
 {
-    if (registerCopy && rio.registered_)
+    if (registerCopy)
+    {
+        if (rio.registered_)
         {
             const_cast<regIOobject&>(rio).checkOut();
+        }
         checkIn();
     }
 }