Add absolute_path feature flag to protobuf build script

Author: windows-fryer

rust/release_crates/protobuf/build.rs

@@ -5,6 +5,8 @@
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 
+#![feature(absolute_path)]
+
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 
 fn main() {