Fix some warnings

Author: ogoffart

Cargo.toml

@@ -11,3 +11,5 @@ members = [
     'examples/qenum',
     'examples/nested_qobjects',
 ]
+
+resolver = "2"

qttypes/build.rs

@@ -211,9 +211,10 @@ fn main() {
             ""
         };
 
+    /* https://github.com/rust-lang/cargo/issues/9562
     if std::env::var("CARGO_CFG_TARGET_FAMILY").as_ref().map(|s| s.as_ref()) == Ok("unix") {
         println!("cargo:rustc-cdylib-link-arg=-Wl,-rpath,{}", &qt_library_path);
-    }
+    } */
 
     println!("cargo:rustc-link-search{}={}", macos_lib_search, &qt_library_path);