Update Cargo.toml

Author: dskkato

Cargo.toml

@@ -29,7 +29,7 @@ byteorder = "1.4.3"
 crc = "3.0.0"
 half = "2.1.0"
 # This is used internally but not intended to be exposed through the API.
-protobuf = "=2.27.1"
+protobuf = "2.27.1"
 # Enables conversions between ndarray::Array objects and tensorflow::Tensor
 ndarray = { version = "0.15.6", optional = true }
 rustversion = "1.0.9"