misc: fix minor bugs (#906)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change

Fix hang when a DLL using the SDK calls `log_fatal` (deadlock)

Fix spicecfg crashing if API server fails to bind (make websocket
teardown conditional)

## Testing

src/spice2x/api/controller.h

@@ -41,21 +41,21 @@ namespace api {
         bool pretty;
 
         // server
-        WebSocketController *websocket;
+        WebSocketController *websocket = nullptr;
         std::vector<SerialController *> serial;
         std::vector<std::thread> server_workers;
         std::vector<std::thread> server_handlers;
         std::mutex server_handlers_m;
         std::vector<api::ClientState *> client_states;
         std::mutex client_states_m;
-        SOCKET server;
+        SOCKET server = INVALID_SOCKET;
         void server_worker();
         void connection_handler(ClientState client_state);
 
     public:
 
         // state
-        bool server_running;
+        bool server_running = false;
 
         // constructor / destructor
         Controller(unsigned short port, std::string password, bool pretty);