Fixes for commit c7fdfefc saving of tagged values to XMI:

umbrello/uml1model/stereotype.cpp
- In function saveToXMI1 case !m_attrDefs.isEmpty() loop over m_attrDefs
  call writer.writeEndElement() to close the opened <UML:Attribute>.

umbrello/uml1model/umlobject.cpp
- In function save1end case m_TaggedValues.count(), after end of loop
  over m_TaggedValues call writer.writeEndElement() to close the opened
  <UML:ModelElement.taggedValues>.

CCBUG: 73847