Add translatable error message for when we cannot connect to the sound server, as "Cannot open resource for writing" ...

Original commit message from CVS:
* ext/esd/esdsink.c: (gst_esdsink_open), (gst_esdsink_prepare):
* ext/esd/gstesd.c: (plugin_init):
* po/POTFILES.in:
Add translatable error message for when we cannot
connect to the sound server, as "Cannot open resource
for writing" isn't really an acceptable message to show
to the user in this case.