message: Pin protobuf 2.14 until our MSRV passes 1.44.1
diff: @@ -17,7 +17,7 @@ bs58 = { version = "0.3", features = ["check"] }
  ff = { version = "0.6", path = "../ff" }
  hex = "0.3"
  pairing = { version = "0.16", path = "../pairing" }
  -protobuf = "2"
  +protobuf = "=2.14.0" # 2.15 has MSRV of 1.44.1
  subtle = "2"
  zcash_primitives = { version = "0.2", path = "../zcash_primitives" }
  