The following files (libeay32.dll, openssl.exe and ssleay32.dll) I recommend that you copy them to a new folder first (all the ones mentioned above, which you just have in the program folder) just in case you might need them later. I am attaching a Proxo_OpenSSL_101Q_DLLs.zip (libeay32.dll, openssl.exe and ssleay32.dll) and a ProxomitronReborn_4605R.zip (proxo.exe) file.
Unzip and copy them to the program folder. The Proxomitron.exe file should remain in the program folder where you will use the previously copied proxo.exe file to run the Proxomitron program.
After running the proxo.exe file, the popup window should no longer appear, at least for me it no longer appeared.
Proxo_OpenSSL_101Q_DLLs.zip and ProxomitronReborn_4605R.zip files is attached.