fix: deadlock in check audio

When call state is RINGING manager will enumerate through all calls
to check current call. It will cause lock when subcall and parent call
update state at the same time.

Change-Id: I0850ea685046cf3c981700e524ca184becdb96e5

src/call.cpp

@@ -110,7 +110,11 @@ Call::Call(Account& account, const std::string& id, Call::CallType type,
         }
 
         checkPendingIM();
-        checkAudio();
+        std::weak_ptr<Call> callWkPtr = shared_from_this();
+        runOnMainThread([callWkPtr]{
+            if (auto call = callWkPtr.lock())
+                call->checkAudio();
+        });
 
         // if call just started ringing, schedule call timeout
         if (type_ == CallType::INCOMING and cnx_state == ConnectionState::RINGING) {