check: Fix dash mpd unit test

check: Fix dash mpd unit test

Unexpected critical/warning: g_object_set_is_valid_property: object class 'GstMPDBaseURLNode' has no property named 'service location'

Stack trace:
gst_debug_get_stack_trace (gstinfo.c:3021)
gst_check_log_critical_func (gstcheck.c:281)
g_logv (gmessages.c:1350)
g_log (gmessages.c:1415)
g_object_set_valist (gobject.c:2327)
gst_mpd_client_add_baseurl_node (gstmpdclient.c:3142)
dash_mpdparser_check_mpd_client_set_methods (dash_mpd.c:6192)
srunner_run_tagged (check_run.c:465)
gst_check_run_suite (gstcheck.c:1086)
main (dash_mpd.c:6521)
__libc_start_main (libc-start.c:308)
_start (/home/bilboed/work/devel/gst-build/build/subprojects/gst-plugins-bad/tests/check/elements_dash_mpd:0x40554a)