Update constants.rs

Update the PROTOCOL_VERSION to correspond to the NU6 upgrade. **THIS CHANGE WILL BE REQUIRED AGAIN WITH FORTHCOMING TRANSACTION FORMAT CHANGES**

src/protocol/message/constants.rs

@@ -12,7 +12,7 @@ pub const HEADER_LEN: usize = 24;
 pub const MAX_MESSAGE_LEN: usize = 2 * 1024 * 1024;
 
 /// The current network protocol version number.
-pub const PROTOCOL_VERSION: u32 = 170_100;
+pub const PROTOCOL_VERSION: u32 = 170_120;
 /// The current network version identifier.
 pub const MAGIC_TESTNET: [u8; MAGIC_LEN] = [0xfa, 0x1a, 0xf9, 0xbf];
 pub const MAGIC_MAINNET: [u8; MAGIC_LEN] = [0x24, 0xe9, 0x27, 0x64];