package/htpdate: fix static openssl build

Fix the following static build failure with openssl raised since bump to
version 1.3.3 in commit 163509a8:

/home/buildroot/autobuild/instance-3/output-1/host/opt/ext-toolchain/bin/../lib/gcc/sh4-buildroot-linux-uclibc/10.3.0/../../../../sh4-buildroot-linux-uclibc/bin/ld: /home/buildroot/autobuild/instance-3/output-1/host/sh4-buildroot-linux-uclibc/sysroot/usr/lib/libssl.a(rec_layer_d1.o): in function `DTLS_RECORD_LAYER_new':
rec_layer_d1.c:(.text+0x124): undefined reference to `CRYPTO_malloc'

Fixes:
 - http://autobuild.buildroot.org/results/75ad8515916dfa056b17c97fdd95c7eb4d83a304



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