whitelist character does not work for 4.0 api

[wosiu]

tested 4.00.00alpha and master (2b854e3)
It does not take any effect when setting variable: "tessedit_char_whitelist" like:

pars_vec.push_back("tessedit_char_whitelist");
pars_values.push_back("1234567890");
api->Init(NULL, "eng", tesseract::OEM_LSTM_ONLY, NULL, 0, &pars_vec, &pars_values, false);

OR before init or after init:
api->SetVariable("tessedit_char_whitelist", "1234567890");

However when you change from OEM_LSTM_ONLY to OEM_TESSERACT_ONLY it works fine.

Same story for command line:
(for master) When you set in command line:
tesseract --oem 1 D1.png stdout -c tessedit_char_whitelist=1234567890
oem 1 means LSTM only - whitelist does not take effect
if you change oem to 0 (Original Tesseract Only) it works fine.

[amitdo]

Already reported in #751

[wosiu]

duplicated