Move Jenkins timeout into parallel_nodes block

Jenkinsfile

@@ -1,5 +1,5 @@
-timeout(time: 2, unit: "HOURS") {
-    parallel_nodes(['linux && cura', 'windows && cura']) {
+parallel_nodes(['linux && cura', 'windows && cura']) {
+    timeout(time: 2, unit: "HOURS") {
         // Prepare building
         stage('Prepare') {
             // Ensure we start with a clean build directory.