luci-app-ssr-plus: disable_mtu_discovery->disablePathMTUDiscovery

QUIC 参数
`````
quic:
  initStreamReceiveWindow: 8388608 
  maxStreamReceiveWindow: 8388608 
  initConnReceiveWindow: 20971520 
  maxConnReceiveWindow: 20971520 
  maxIdleTimeout: 30s 
  keepAlivePeriod: 10s 
  disablePathMTUDiscovery: false 
``````

luci-app-ssr-plus/root/usr/share/shadowsocksr/gen_config.lua

@@ -429,7 +429,7 @@ local hysteria = {
 		maxConnReceiveWindow = (server.maxconnreceivewindow and server.maxconnreceivewindow or nil),
 		maxIdleTimeout = (tonumber(server.maxidletimeout) and tonumber(server.maxidletimeout) .. "s" or nil),
 		keepAlivePeriod = (tonumber(server.keepaliveperiod) and tonumber(server.keepaliveperiod) .. "s" or nil),
-		disable_mtu_discovery = (server.disablepathmtudiscovery == "1") and true or false
+		disablePathMTUDiscovery = (server.disablepathmtudiscovery == "1") and true or false
 	} or nil,
 	auth = server.hy2_auth,
 	tls = (server.tls_host) and {