fix: concurrent map access panic in webSocketServer.Close()

Signed-off-by: Enrique Lacal <enrique.lacal@kaleido.io>

Author: EnriqueL8

pkg/wsserver/wsserver.go

@@ -127,7 +127,13 @@ func (s *webSocketServer) connectionClosed(c *webSocketConnection) {
 }
 
 func (s *webSocketServer) Close() {
+	s.mux.Lock()
+	conns := make([]*webSocketConnection, 0, len(s.connections))
 	for _, c := range s.connections {
+		conns = append(conns, c)
+	}
+	s.mux.Unlock()
+	for _, c := range conns {
 		c.close()
 	}
 }