netcat-openbsd: add source and license hashes

Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/netcat-openbsd/netcat-openbsd.hash

@@ -0,0 +1,3 @@
+# Locally calculated
+sha256 f587c02139aedb0bae12fdaef94f8c00649a0b4d603b5a22612e42cb317ba7cf netcat-openbsd-debian_1.178-3.tar.gz
+sha256 e2e86d58c38f044a49f51e45515747585db58a2305419c73323eaad88fcaef5c debian/copyright