call: avoid potential deadlock

Do not emit CallSignal::StateChange while locked. Because if the
client uses any method that lock callMutex_ it will be a deadlock.

Change-Id: I49aa7cb4ee60b23ef069751a7c1abbf4c9fcec95

src/call.cpp

@@ -240,7 +240,7 @@ Call::validStateTransition(CallState newState)
 bool
 Call::setState(CallState call_state, ConnectionState cnx_state, signed code)
 {
-    std::lock_guard<std::recursive_mutex> lock(callMutex_);
+    std::unique_lock<std::recursive_mutex> lock(callMutex_);
     JAMI_DBG("[call:%s] state change %u/%u, cnx %u/%u, code %d",
              id_.c_str(),
              (unsigned) callState_,
@@ -275,6 +275,7 @@ Call::setState(CallState call_state, ConnectionState cnx_state, signed code)
                      id_.c_str(),
                      new_client_state.c_str(),
                      code);
+            lock.unlock();
             emitSignal<DRing::CallSignal::StateChange>(id_, new_client_state, code);
         }
     }