several one-line panic, race, and logic fixes (#7766)

cmd/platform/test.go

@@ -77,7 +77,7 @@ func serverForWebClientTestsCmdF(cmd *cobra.Command, args []string) error {
 	wsapi.Init(a, a.Srv.WebSocketRouter)
 	a.UpdateConfig(setupClientTests)
 
-	c := make(chan os.Signal)
+	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
 	<-c