Some packages don't have shrinkwrap file which
means no npmsw uri is provided in the recipe.
(From OE-Core rev: 47760b0d7d66b2b68ee197d359f0b7b17374d742)
Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>