bug in setting up call state at startup

Submitted by Kai Vehmanen

Assigned to Pekka Pessi @ppessi

Link to original bug (#33292)

Description

STEPS:

1. do not start tpring
2. make a call to number X with ofono
3. start tpring
4. tpring detects the ongoing calls and creates channels for them
5. try to create a new call to X

EXPECTED OUTCOME: a new, separate channel is established to X (and the original call is put on hold)

ACTUAL OUTCOME: assert hit: --cut-- ERROR:call.c:648:modem_call_set_handler: assertion failed: (success) --cut--

Version: git master