adapt to new JSON adapter

unblock Startup(), see code comment why

CpEpEngine.cpp

@@ -1835,7 +1835,13 @@ STDMETHODIMP CpEpEngine::Startup()
 {
     try
     {
-        pEp::CallbackDispatcher::start_sync();
+        // this must be unblocked, because it's not possible to have two API calls in parallel
+        // start_sync() may send notifyHandshake() to ask for a passphrase; when this happens
+        // the client needs to call ConfigPassphrase() while the startup process is being executed
+        // so we need to return from Startup() immediately to make this possible
+
+        auto sync_starter_thread = std::thread(pEp::CallbackDispatcher::start_sync);
+        sync_starter_thread.detach();
     }
     catch (bad_alloc&) {
         return E_OUTOFMEMORY;

LocalJSONAdapter.cpp

@@ -1,9 +1,15 @@
 #include "stdafx.h"
 #include "LocalJSONAdapter.h"
+#include <pEp/Adapter.hh>
 
 void startSync() { }
 void stopSync() { }
 
+std::thread::id LocalJSONAdapter::get_sync_thread_id() const
+{
+	return pEp::Adapter::sync_thread_id();
+}
+
 LocalJSONAdapter& LocalJSONAdapter::createInstance()
 {
 	return dynamic_cast<LocalJSONAdapter&>(JsonAdapter::createInstance(new LocalJSONAdapter()));

LocalJSONAdapter.h

@@ -7,6 +7,7 @@ class LocalJSONAdapter :
 {
 public:
 	static LocalJSONAdapter& createInstance();
+	std::thread::id get_sync_thread_id() const;
 
 protected:
 	virtual inject_sync_event_t getInjectSyncEvent() const override