Important: I do not expect anything to make this code run with OpenSSL 1.0.2, I just want to outline the following incompat from an example:
Here [1] we say that our code run with 1.0.2 or newer. Let's consider we'd try, then let's have a look at 2c22764c49c06c4a6ccbbcc08021be43de7eba49 SSL#version() and SSL#versionString() use functions in C which aren't listed here [2], so I need to assume that the code isn't compatible anymore.

If my understanding is correct, we should abandon 1.2.x soon and start with 1.3.x, raise to 1.1.1 minimum and remove old pre-1.1.1 checks.

Again: I don't expect or want someone to use it with 1.0.2, but pointing out that our setup is incorrect.

[1] https://github.com/apache/tomcat-native/blob/a2aa5aff32ab1fee2bcdd2fce1446786633eb0ee/native/build/tcnative.m4#L247-L254
[2] https://www.openssl.org/docs/man1.0.2/man3/