package/rtty: fix static build with openssl

Fixes:
 - http://autobuild.buildroot.org/results/6105b69d8598f0033044a26f53a768e2d4b2915e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2 files changed