package/amazon-ecr-credential-helper: add LICENSE hash
The hash has for the license file been missing since the package was
introduced in commit 9a9580622545 (package/amazon-ecr-credential-helper:
new package).
Add it now.
Signed-off-by: Yann E. MORIN <yann.morin@orange.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>