[565546] Provide support for launching a product with an embedded JRE

Try producing tar with --format=gnu; make it the first argument.

https://bugs.eclipse.org/bugs/show_bug.cgi?id=565546
diff --git a/products/org.eclipse.oomph.setup.installer.product/repackage-products.sh b/products/org.eclipse.oomph.setup.installer.product/repackage-products.sh
index fbd712d..024b55f 100644
--- a/products/org.eclipse.oomph.setup.installer.product/repackage-products.sh
+++ b/products/org.eclipse.oomph.setup.installer.product/repackage-products.sh
@@ -30,7 +30,7 @@
       mkdir -p tmp
       cd tmp
       unzip -qq ../$i
-      tar -cf --format=gnu ../${i%.zip}.tar *
+      tar --format=gnu -cf ../${i%.zip}.tar *
       cd ..
       rm -rf tmp
       product=${i%.zip}.tar