I am still having the issue as well after installing libssl-dev, and I also can not see any ssl files in /usr/lib
I then put in this command
root@aspen:/usr/lib# sudo apt-get install libssl-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
libssl-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
root@aspen:/usr/lib# ls libssl*
ls: cannot access libssl*: No such file or directory
... which showed a libssl.so inside of /usr/lib/x86_64-linux-gnu/
I made a link to it with:
..and then was able to configure and make my nrpe install!
ln -s /usr/lib/x86_64-linux-gnu/libssl.so /usr/lib/libssl.so