OpenLP says servicefile containing songs with linked is corrupt when opening on different computer

[Tomas Groth]

Confirmed using trunk (and beta 2.1.1).
I created a servicefile with a song with linked audio on a windows pc, moved it to a linux box and got a popup saying the file was corrupt. The second time I tried to open it it worked...

The underlying traceback is this:
  File "/home/tgc/openlp/code/bugfixes9/openlp/core/ui/servicemanager.py", line 771, in load_file
    self.process_service_items(items)
  File "/home/tgc/openlp/code/bugfixes9/openlp/core/common/openlpmixin.py", line 65, in wrapped
    raise e
  File "/home/tgc/openlp/code/bugfixes9/openlp/core/common/openlpmixin.py", line 61, in wrapped
    return func(*args, **kwargs)
  File "/home/tgc/openlp/code/bugfixes9/openlp/core/ui/servicemanager.py", line 830, in process_service_items
    new_item = Registry().get(service_item.name).service_load(service_item)
  File "/home/tgc/openlp/code/bugfixes9/openlp/plugins/songs/lib/mediaitem.py", line 549, in service_load
    self._update_background_audio(song, item)
  File "/home/tgc/openlp/code/bugfixes9/openlp/plugins/songs/lib/mediaitem.py", line 93, in _update_background_audio
    shutil.copyfile(os.path.join(AppLocation.get_section_data_path('servicemanager'), bga), dest_file)
  File "/usr/lib/python3.4/shutil.py", line 107, in copyfile
    with open(src, 'rb') as fsrc:
FileNotFoundError: [Errno 2] Ingen sådan fil eller filkatalog: '/home/tgc/.local/share/openlp/servicemanager/C:\\Users\\tgc\\AppData\\Roaming\\openlp\\data\\songs\\audio\\1\\Revival.mp3'

The problem lies in the way treat the path from the zip and/or the serviceitem.