Fix SSD1306 OLED pinout on TLORA_V1_3

The V1.3 board OLED pinout changed from V1
Now on pin SDA(21) and SCL(22) not SDA(4) and SCL(15)

LILYGO Product Page
http://www.lilygo.cn/prod_view.aspx?TypeId=50060&Id=1253&FId=t3:50060:3

Product Pin
https://ae01.alicdn.com/kf/H098cb5d5159841b398fcfd4ebf705725W.jpg

src/configuration.h

@@ -428,8 +428,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #define BATTERY_PIN 35 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage
 
-#define I2C_SDA 4 // I2C pins for this board
-#define I2C_SCL 15
+#define I2C_SDA 21 // I2C pins for this board
+#define I2C_SCL 22
 
 #define RESET_OLED 16 // If defined, this pin will be used to reset the display controller