tests: Replace is_connected() with is_registered()
API was renamed and old name deprecated, let's use it everywhere.
Change-Id: Ic91dddcfd1a5a17c35d15a8a14628b3923229523
diff --git a/sysmocom/suites/gprs/ping_idle_ping.py b/sysmocom/suites/gprs/ping_idle_ping.py
index 88ecbdb..099650c 100755
--- a/sysmocom/suites/gprs/ping_idle_ping.py
+++ b/sysmocom/suites/gprs/ping_idle_ping.py
@@ -45,7 +45,7 @@
ms.log_info()
print('waiting for modems to attach...')
-wait(ms.is_connected, msc.mcc_mnc())
+wait(ms.is_registered, msc.mcc_mnc())
wait(msc.subscriber_attached, ms)
print('waiting for modems to attach to data services...')