Oh... that was in the blynk header... no wonder I was a bit confused when I read that the first time

duh! Ok, so you made that change to the copy of the blynk library included with the oak (so for the 1.0.1 core, that would be located in %userprofile%\AppData\Local\Arduino15\packages\digistump\hardware\oak\1.0.1\libraries\Blynk if you're using Arduino 1.6.6 onwards (change the Local to Roaming for earler IDE versions)).
I would be tempted to wrap that change in ifdef tags (unless anyone else has a better way to detect compilation against the oak core), and that could then go into the standard blynk library... although since that header seems to be Oak specific... there isn't really a need, and the
void connectWiFi(const char* ssid, const char* pass) they use can actually be removed as it is actually invalid for the oak...
#ifdef ARDUINO_ESP8266_OAK
// ADDED for Oak (by exeng) - similar to standard ESP8266 version above, but without args to connectWiFi()
void connectWiFi()
{
BLYNK_LOG("Oak in connect WiFi");
WiFi.begin(); // Oak is already has a configured SSID to connect to
while (WiFi.status() != WL_CONNECTED) {
::delay(10000); // delay 10 seconds
}
BLYNK_LOG("Connected to WiFi");
IPAddress myip = WiFi.localIP();
BLYNK_LOG("My IP: %d.%d.%d.%d", myip[0], myip[1], myip[2], myip[3]);
}
// END of ADDED for Oak (by exeng)
#else
// Original standard version of function, for use with ESP8266 boards
void connectWiFi(const char* ssid, const char* pass)
{
/*BLYNK_LOG("Connecting to %s", ssid);
if (pass && strlen(pass)) {
WiFi.begin(ssid, pass);
} else {
WiFi.begin(ssid);
}*/
while (WiFi.status() != WL_CONNECTED) {
::delay(500);
}
BLYNK_LOG("Connected to WiFi");
IPAddress myip = WiFi.localIP();
BLYNK_LOG("My IP: %d.%d.%d.%d", myip[0], myip[1], myip[2], myip[3]);
}
#endif