nuttcp: add tarball hash

Fixes (eventually, once the bad downloads are deleted):
http://autobuild.buildroot.net/results/055/0556ffec533af65392c24f7c74092d3282245c95/
http://autobuild.buildroot.net/results/481/4810de845bac9ec28cba86379de0f8c554038ea0/
http://autobuild.buildroot.net/results/384/384b627a104793f460072aa43381a8c2d703a693/
http://autobuild.buildroot.net/results/2f8/2f8574a5bc692e3dfb803b420fb6ae2dc420cfed/

And many others.

There's no upstream hash, but this matches E.G. Freebsd:

http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2009-August/170685.html

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/nuttcp/nuttcp.hash

@@ -0,0 +1,2 @@
+# From http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2009-August/170685.html
+sha256	054e96d9d68fe917df6f25fab15c7755bdd480f6420d7d48d9194a1a52378169  nuttcp-6.1.2.tar.bz2