feat: bring back compatibility with Rust 1.11.0

Apparently code depended on regression in the stable rustc to work.
Newest beta rustc (1.14) fixes the regression, so the code would no
longer work.

rust-lang/rust#37959

Author: zetok

README.md

@@ -27,7 +27,7 @@ Current [API docs](https://zetok.github.io/tox) are a subject to changes.
 | libsodium | >=1.0.0 |
 
 ## Building
-Fairly simple. You'll need [Rust] >= 1.12.1 and [libsodium].
+Fairly simple. You'll need [Rust] >= 1.11.0 and [libsodium].
 
 When you'll have deps, build debug version with
 ```bash

src/toxcore/state_format/old.rs

@@ -1444,10 +1444,9 @@ fn friend_state_parse_bytes_test() {
             let mut bytes = fs_bytes.clone();
             // TODO: change to inclusive range (`...`) once gets stabilised
             //       rust #28237
-            for b in 5.. {
+            for b in 5..u8::max_value() {
                 bytes[0] = b;
                 assert_error(&bytes, &format!("Unknown FriendStatus: {}", b));
-                if b == u8::max_value() { break; }
             }
         }
 
@@ -1664,7 +1663,9 @@ fn section_data_parse_bytes_test() {
                 b_sect[4] = num;
                 wrong_skind(&b_sect);
             }
-            for num in 12..255 {
+            // TODO: change to inclusive range (`...`) once gets stabilised
+            //       rust #28237
+            for num in 12..u8::max_value() {
                 b_sect[4] = num;
                 wrong_skind(&b_sect);
             }