Remove global config watcher (#8080)

* remove global config watcher

* keep config watcher disabled for tests

* compile fix

* fix resource leak

app/options.go

@@ -35,3 +35,7 @@ func ConfigFile(file string) Option {
 		a.configFile = file
 	}
 }
+
+func DisableConfigWatch(a *App) {
+	a.disableConfigWatch = true
+}