Merge pull request #340 from TheBlueMatt/2019-11-4m-limit

Drop message decode max length to 4_000_000

src/consensus/encode.rs

@@ -343,7 +343,7 @@ impl<R: Read> ReadExt for R {
 }
 
 /// Maximum size, in bytes, of a vector we are allowed to decode
-pub const MAX_VEC_SIZE: usize = 32 * 1024 * 1024;
+pub const MAX_VEC_SIZE: usize = 4_000_000;
 
 /// Data which can be encoded in a consensus-consistent way
 pub trait Encodable {