context: Rename func to AppIfConfigured (#5397)

modules/caddypki/adminapi.go

@@ -49,20 +49,14 @@ func (a *adminAPI) Provision(ctx caddy.Context) error {
 	a.ctx = ctx
 	a.log = ctx.Logger(a) // TODO: passing in 'a' is a hack until the admin API is officially extensible (see #5032)
 
-	// First check if the PKI app was configured, because
-	// a.ctx.App() has the side effect of instantiating
-	// and provisioning an app even if it wasn't configured.
-	pkiAppConfigured := a.ctx.AppIsConfigured("pki")
-	if !pkiAppConfigured {
-		return nil
-	}
-
-	// Load the PKI app, so we can query it for information.
-	appModule, err := a.ctx.App("pki")
+	// Avoid initializing PKI if it wasn't configured
+	pkiApp, err := a.ctx.AppIfConfigured("pki")
 	if err != nil {
 		return err
 	}
-	a.pkiApp = appModule.(*PKI)
+	if pkiApp != nil {
+		a.pkiApp = pkiApp.(*PKI)
+	}
 
 	return nil
 }