Update to bitflags 2 (#1498)

Author: tottoto

Cargo.lock

@@ -80,7 +80,7 @@ text-indexes-unstable = []
 
 [dependencies]
 base64 = "0.13.0"
-bitflags = "1.1.0"
+bitflags = "2"
 chrono = { version = "0.4.7", default-features = false, features = [
     "clock",
     "std",

Cargo.toml

@@ -407,6 +407,7 @@ const DEFAULT_MAX_MESSAGE_SIZE_BYTES: i32 = 48 * 1024 * 1024;
 
 bitflags! {
     /// Represents the bitwise flags for an OP_MSG as defined in the spec.
+    #[derive(Debug)]
     pub(crate) struct MessageFlags: u32 {
         const CHECKSUM_PRESENT = 0b_0000_0000_0000_0000_0000_0000_0000_0001;
         const MORE_TO_COME     = 0b_0000_0000_0000_0000_0000_0000_0000_0010;