rustbuild: don't try to install rls if ToolState is not Testing

The Dist Step is not ran in that case so we would end up trying to
install something that we didn't dist.

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

src/bootstrap/install.rs

@@ -186,8 +186,11 @@ install!((self, builder, _config),
         install_cargo(builder, self.stage, self.target);
     };
     Rls, "rls", _config.extended, only_hosts: true, {
-        builder.ensure(dist::Rls { stage: self.stage, target: self.target });
-        install_rls(builder, self.stage, self.target);
+        if builder.ensure(dist::Rls { stage: self.stage, target: self.target }).is_some() {
+            install_rls(builder, self.stage, self.target);
+        } else {
+            println!("skipping Install RLS stage{} ({})", self.stage, self.target);
+        }
     };
     Analysis, "analysis", _config.extended, only_hosts: false, {
         builder.ensure(dist::Analysis {