Commit 293e55c breaks old behaviour of AUTH_OPEN on empty passphrase string

[sauttefk]

With commit 293e55c softAP setup with passphrases shorter than 8 characters are rejected strlen(passphrase) < 8.
The old behaviour was to allow an empty passphrase to configure AUTH_OPEN mode.
In a lot of code examples floating around in the internet those empty strings are used so this commit breaks them.

Arduino/libraries/ESP8266WiFi/src/ESP8266WiFiAP.cpp

Line 96 in 293e55c

if(passphrase && (strlen(passphrase) > 63 || strlen(passphrase) < 8)) {

    if(passphrase && (strlen(passphrase) > 63 || strlen(passphrase) < 8)) {
        // fail passphrase to long or short!
        return false;
    }

[stuff deleted]

    if(!passphrase || strlen(passphrase) == 0) {
        conf.authmode = AUTH_OPEN;
        *conf.password = 0;
    } else {
        conf.authmode = AUTH_WPA2_PSK;
        strcpy(reinterpret_cast<char*>(conf.password), passphrase);
    }

I suggest to change line 96, to keep the old behaviour:

    if(*passphrase != 0 && passphrase && (strlen(passphrase) > 63 || strlen(passphrase) < 8)) {

Otherwise, if the new behaviour is desired strlen(passphrase) == 0 on line 109 could be removed.