netsnmp: fix static build failure due to missing -lssl and -lz

netsnmp: fix static build failure due to missing -lssl and -lz

During configure some checking needing -lssl and -lz don't have them
appended to linker tail. Since we are building static this leads to
configure failure because of mandatory functions lack produces:
"configure: error: The DTLS based transports require the libssl library
from OpenSSL to be available and support DTLS"

- Add 1 patch to fix -lssl lack in configure and .ac modules:
upstreamed: https://sourceforge.net/p/net-snmp/code/ci/bd59be8e4e339870a1400f6866a7b73ca11f6460/
- Add 2 patches to fix -lz lack in configure and .ac modules:
1 upstreamed: https://sourceforge.net/p/net-snmp/code/ci/13da2bcde8e22dd0127a668374fdf79bed04d353/
1 in Merge Request: https://sourceforge.net/p/net-snmp/code/merge-requests/19/
- Add NETSNMP_AUTORECONF = YES

Fixes:
http://autobuild.buildroot.net/results/ece/ece7af756c910f65f618c1d04a5de70cc574b5f4/
http://autobuild.buildroot.net/results/2a7/2a7020de6a4095cf9991d09fbe8f6e364783f63b/
http://autobuild.buildroot.net/results/e27/e2787d15f72949cbb347e8a1d344f5f80b4d7697/
http://autobuild.buildroot.net/results/439/4393ce8ddee294f91bdc3e6fb53e08d56fe52184/
http://autobuild.buildroot.net/results/da6/da6bbbbb3a8d8193ec1389b9d976164181e88ae2/
http://autobuild.buildroot.net/results/cf5/cf57686e7620cc0ec361631a9ff906aa0123fdb4/
http://autobuild.buildroot.net/results/104/1043a958314529240627005d1bf21a76f4e6fcf5/
http://autobuild.buildroot.net/results/885/8855545bd09388e0da451a3cb53b312e13b29c2c/
http://autobuild.buildroot.net/results/a3d/a3dab9618a7ed88f94597418a5892c87adc23c66/
http://autobuild.buildroot.net/results/18e/18e70b88c9bcb3b8ede7308e54bba9417d1fd3fb/
http://autobuild.buildroot.net/results/ee3/ee34f65f26da20c0f2fdb9e86bcbddd389f59a29/
http://autobuild.buildroot.net/results/a1e/a1eb848079080ddf7cf2fc9e554cdd63ade0e9aa/
http://autobuild.buildroot.net/results/4dc/4dc8b53ff9f504c0a3dfc2d72c2609ad4d34559b/
http://autobuild.buildroot.net/results/9cc/9cc19e481de20ea0b4b5163e45c5aee525b81229/
http://autobuild.buildroot.net/results/f15/f15c22e0257d7498456049d8aae195ed6a265d2e/
http://autobuild.buildroot.net/results/1b3/1b30f9813a4605056963bfe4532374f725830fda/
http://autobuild.buildroot.net/results/d02/d02afc174ac4c9888f0a2cf725820cc1f05fc4bf/
http://autobuild.buildroot.net/results/57b/57b3f4663058d728987ef848e4b346656cae21d4/
http://autobuild.buildroot.net/results/ed4/ed4c27bdffccc4374ab7f951c30baba8171d30e1/

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>