It doesn't actually do anything.

src/core/CMakeLists.txt:
if(OPENSSL_FOUND)
   set(KSSL_HAVE_SSL 1)
   include_directories(${OPENSSL_INCLUDE_DIR})
endif()

src/core/kssl/ksslsettings.cpp:
#if 0
#if KSSL_HAVE_SSL

It is on my TODO to follow up with upstream, either the openssl check should be commented out, or both things removed completely.