Fix Error on Ubuntu Arm (nervosnetwork#123)

src/high_level.rs

@@ -705,7 +705,7 @@ pub fn spawn_cell(
         let index = look_for_dep_with_hash2(code_hash, hash_type)?;
         let argc = argv.len();
         let mut process_id: u64 = 0;
-        let argv_ptr: Vec<*const i8> = argv.iter().map(|e| e.as_ptr()).collect();
+        let argv_ptr: Vec<*const i8> = argv.iter().map(|e| e.as_ptr() as *const i8).collect();
         let mut spgs = syscalls::SpawnArgs {
             argc: argc as u64,
             argv: argv_ptr.as_ptr(),