Update FP for tls.mbed.org (#7479)

Author: earlephilhower

libraries/ESP8266HTTPClient/examples/StreamHttpsClient/StreamHttpsClient.ino

@@ -50,7 +50,7 @@ void loop() {
     Serial.print("[HTTPS] begin...\n");
 
     // configure server and url
-    const uint8_t fingerprint[20] = {0xEB, 0xD9, 0xDF, 0x37, 0xC2, 0xCC, 0x84, 0x89, 0x00, 0xA0, 0x58, 0x52, 0x24, 0x04, 0xE4, 0x37, 0x3E, 0x2B, 0xF1, 0x41};
+    const uint8_t fingerprint[20] = {0x15, 0x77, 0xdc, 0x04, 0x7c, 0x00, 0xf8, 0x70, 0x09, 0x34, 0x24, 0xf4, 0xd3, 0xa1, 0x7a, 0x6c, 0x1e, 0xa3, 0xe0, 0x2a};
 
     client->setFingerprint(fingerprint);