Bug while editing a VNF/NS descriptor

	*Changed the content type to gzip in headers to support .gz files while editing VNF and NS descriptors.

Change-Id: Ic9137f8f08048f0c8c3bb2dd4fe498c1f6eaecaf
Signed-off-by: harshini.r <harshini.r@tataelxsi.co.in>