Bump version for new RB.

Author: LexManos

src/main/java/net/minecraftforge/common/ForgeVersion.java

@@ -23,7 +23,7 @@ public class ForgeVersion
     //This number is incremented every minecraft release, never reset
     public static final int minorVersion    = 13;
     //This number is incremented every time a interface changes or new major feature is added, and reset every Minecraft version
-    public static final int revisionVersion = 3;
+    public static final int revisionVersion = 4;
     //This number is incremented every time Jenkins builds Forge, and never reset. Should always be 0 in the repo code.
     public static final int buildVersion    = 0;