ms: Fix and use ms msisdn() getter
The getter method was named the same as the itnernal field, and hence
when used it would fail since the intenral field would be sleect and
fail to be called.
Change-Id: I2f631eb6256eb0e065f41d5b7531395c4a054cd8
diff --git a/sysmocom/suites/ussd/assert_extension.py b/sysmocom/suites/ussd/assert_extension.py
index 87f2ee5..11a5c5b 100755
--- a/sysmocom/suites/ussd/assert_extension.py
+++ b/sysmocom/suites/ussd/assert_extension.py
@@ -47,4 +47,4 @@
print('Sending ussd code %s' % USSD_COMMAND_GET_EXTENSION)
response = ms.ussd_send(USSD_COMMAND_GET_EXTENSION)
log('got ussd response: %r' % repr(response))
-assert response.endswith(' ' + ms.msisdn)
+assert response.endswith(' ' + ms.msisdn())