remove experimental rust features

allow unsafe on function that calls C

src/rust/protover/lib.rs

-#![feature(inclusive_range_syntax)]
-
 //! Copyright (c) 2016-2017, The Tor Project, Inc. */
 //! See LICENSE for licensing information */
 

src/rust/protover/protover.rs

@@ -362,7 +362,8 @@ fn expand_version_range(range: &str) -> Result<Vec<u32>, &'static str> {
         "cannot parse protocol range upper bound",
     ))?;
 
-    Ok((lower..=higher).collect())
+    // We can use inclusive range syntax when it becomes stable.
+    Ok((lower..higher+1).collect())
 }
 
 /// Checks to see if there is a continuous range of integers, starting at the

src/rust/tor_allocate/tor_allocate.rs

@@ -25,6 +25,10 @@ extern "C" fn tor_malloc_ ( size: usize) ->  *mut c_void {
 ///
 /// A `*mut c_char` that should be freed by tor_free in C
 ///
+/// Allow unused unsafe as at compile-time, we get warnings that unsafe is not
+/// needed even though this calls tor_malloc in C.
+///
+#[allow(unused_unsafe)]
 pub fn allocate_and_copy_string(src: &String) -> *mut c_char {
     let bytes: &[u8] = src.as_bytes();