Correct URL for MythXML.getExpiring()

This changes getExpiring() from using the incorrect "Dvr/GetExpiring" to
the correct "Dvr/GetExpiringList".

Fixes #10968

Signed-off-by: Raymond Wagner <rwagner@mythtv.org>

mythtv/bindings/python/MythTV/methodheap.py

@@ -1199,7 +1199,7 @@ def getExpiring(self):
         """
         Returns a list of Program objects for expiring shows on the backend.
         """
-        for prog in self._request('Dvr/GetExpiring')\
+        for prog in self._request('Dvr/GetExpiringList')\
                     .readJSON()['ProgramList']['Programs']:
             yield Program.fromJSON(prog, self.db)