Replace try! by ?

src/load_extension_guard.rs

@@ -8,7 +8,7 @@ use {Connection, Result};
 /// # use rusqlite::{Connection, Result, LoadExtensionGuard};
 /// # use std::path::{Path};
 /// fn load_my_extension(conn: &Connection) -> Result<()> {
-///     let _guard = try!(LoadExtensionGuard::new(conn));
+///     let _guard = LoadExtensionGuard::new(conn)?;
 ///
 ///     conn.load_extension(Path::new("my_sqlite_extension"), None)
 /// }