This removes the code introduced in #4399 that attempts to add additional entroy to the OpenSSL PRNG using RAND_event(). This is specific to bitcoin-qt running on Windows.
0RAND_event() collects the entropy from Windows events such as mouse movements and other user interaction.
1It should be called with the iMsg, wParam and lParam arguments of all messages sent to the window procedure.
2It will estimate the entropy contained in the event message (if any), and add it to the PRNG.
3The program can then process the messages as usual.
Besides BIP70, this is the last place we are directly using OpenSSL in the GUI code. All other OpenSSL usage is in random.cpp.
Note that we are still also still doing other Windows specific gathering using RandAddSeedPerfmon and RAND_screen() on top of the other generation we do.
Also note that if RAND_event returns 0 here (PRNG has NOT been seeded with enough data), we’re just logging a single message and continuing, which also seems less than ideal.
