I cannot quickly reproduce it, what is your libssl version? As I could guess from the issue description, you run on RHEL 7 with kernel 3.10, so it can be pretty old libssl there.
Also, if you think of some changes that could fix it, just post the patch or make a pull request to analyze and merge if all ok.
Moreover, maybe you can test with master branch and setting `rpc_exec_delta=5` global parameter in kamailio.cfg to see if the behaviour changes in any way. This adds a limit of one tls reload per 5 secs.