iputils: Initialize libgcrypt

Initialize libgcrypt on first use otherwise
there comes below warning when check the status
of the ninfod.service.
 # systemctl status ninfod.service
 * ninfod.service - Respond to IPv6 Node Information Queries
 Loaded: loaded (/lib/systemd/system/ninfod.service; enabled; vendor preset: enabled)
 Active: active (running) since Wed 2020-04-29 05:18:21 UTC; 36s ago
 Docs: man:ninfod(8)
 Main PID: 347 (ninfod)
 Tasks: 1 (limit: 9382)
 Memory: 1.2M
 CGroup: /system.slice/ninfod.service
 `-347 /sbin/ninfod -d

 Apr 29 05:18:21 intel-x86-64 systemd[1]: Started Respond to IPv6 Node Information Queries.
 Apr 29 05:18:24 intel-x86-64 ninfod[347]: Libgcrypt warning: missing initialization - please fix the application

Reference: https://salsa.debian.org/apt-team/apt/-/commit/4f489a8c7954cbbc9613e6b671c8efe87b9ced8c



Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>