Update jenkins badge to use master branch (GeyserMC#80)

Author: jackson-57

README.md

@@ -1,7 +1,7 @@
 # Floodgate
 
 [![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
-[![Build Status](https://ci.nukkitx.com/job/GeyserMC/job/Floodgate/job/development/badge/icon)](https://ci.nukkitx.com/job/GeyserMC/job/Floodgate/job/development/)
+[![Build Status](https://ci.nukkitx.com/job/GeyserMC/job/Floodgate/job/master/badge/icon)](https://ci.nukkitx.com/job/GeyserMC/job/Floodgate/job/master/)
 [![Discord](https://img.shields.io/discord/613163671870242838.svg?color=%237289da&label=discord)](http://discord.geysermc.org/)
 [![HitCount](https://hits.dwyl.com/GeyserMC/Floodgate.svg)](http://hits.dwyl.com/GeyserMC/Floodgate)