[+] Make update checking configurable

Author: WangYihang

lib/runtime/config.example.yml

@@ -19,4 +19,6 @@ restful:
   host: "127.0.0.1"
   port: 7331
   # `enable: true` means starting RESTful Server when Platypus starts.
-  enable: true
+  enable: true
+# Check new releases from GitHub when starting Platypus
+update: true

platypus.go

@@ -25,12 +25,10 @@ type Config struct {
 		Port   int16  `yaml:"port"`
 		Enable bool   `yaml:"enable"`
 	}
+	Update bool
 }
 
 func main() {
-	// Detect new version
-	update.ConfirmAndSelfUpdate()
-
 	// Detect and create config file
 	configFilename := "config.yml"
 	if !fs.FileExists(configFilename) {
@@ -46,6 +44,11 @@ func main() {
 	// Create context
 	context.CreateContext()
 
+	// Detect new version
+	if config.Update {
+		update.ConfirmAndSelfUpdate()
+	}
+
 	// Init servers from config file
 	for _, s := range config.Servers {
 		server := context.CreateTCPServer(s.Host, uint16(s.Port), s.HashFormat)