Replace reprod patched mixin with upstream + gradle task for fixing refmap

gradle/reprod/patches/mixin/0005-Replace-fernflower-SNAPSHOT-depencency.patch

@@ -1,25 +0,0 @@
-From c66ba83e4b27f6f094c2dcdaaac095d3ca69b41c Mon Sep 17 00:00:00 2001
-From: Jonas Herzig <me@johni0702.de>
-Date: Tue, 8 Aug 2017 19:35:08 +0200
-Subject: [PATCH 5/7] Replace fernflower SNAPSHOT depencency
-
----
- build.gradle | 4 ++--
- 1 file changed, 2 insertions(+), 2 deletions(-)
-
-diff --git a/build.gradle b/build.gradle
-index f8598a3..e9a965b 100644
---- a/build.gradle
-+++ b/build.gradle
-@@ -143,7 +143,7 @@ dependencies {
- 
-     // Fernflower decompiler
-     fernflowerCompile configurations.compile
--    fernflowerCompile 'org.jetbrains.java.decompiler:fernflower:sponge-SNAPSHOT'
-+    fernflowerCompile 'reprod:fernflower:0'
- 
-     // LegacyLauncher service
-     launchwrapperCompile configurations.compile
--- 
-2.5.5
-