Fix rust issues (pin log, run bindgen) (#1005)

* rust: Pin log version to =0.4.18

The 0.4.19 requires rustc 1.60, but currently we support 1.58.
Pinning it is not a big deal since it's development dependecy for
tests and examples.

* rust: Regenerate and update lib.rs

bindgen was updated again and changed something which resulted in
new output (seems like some internal constants are removed).

src/wrappers/themis/rust/Cargo.toml

@@ -33,5 +33,6 @@ base64 = "0.10.0"
 byteorder = "1.2.7"
 clap = "2.32"
 lazy_static = "1.2.0"
-log = "0.4.6"
+# it can be unpinned when we update the minimum supported version of rustc
+log = "=0.4.18"
 env_logger = "0.6.0"

src/wrappers/themis/rust/libthemis-sys/src/lib.rs

@@ -44,9 +44,6 @@ pub const THEMIS_SCOMPARE_SEND_OUTPUT_TO_PEER: u32 = 1;
 pub const THEMIS_SCOMPARE_MATCH: u32 = 21;
 pub const THEMIS_SCOMPARE_NO_MATCH: u32 = 22;
 pub const THEMIS_SCOMPARE_NOT_READY: u32 = 0;
-pub const STATE_IDLE: u32 = 0;
-pub const STATE_NEGOTIATING: u32 = 1;
-pub const STATE_ESTABLISHED: u32 = 2;
 pub type themis_status_t = i32;
 extern "C" {
     pub fn themis_secure_cell_encrypt_seal(
@@ -289,6 +286,9 @@ extern "C" {
         message_length: *mut usize,
     ) -> themis_status_t;
 }
+pub const STATE_IDLE: u32 = 0;
+pub const STATE_NEGOTIATING: u32 = 1;
+pub const STATE_ESTABLISHED: u32 = 2;
 pub type send_protocol_data_callback = ::std::option::Option<
     unsafe extern "C" fn(
         data: *const u8,