Update cdc_multi.ino

fixed a typo

Author: BadCD

examples/CDC/cdc_multi/cdc_multi.ino

@@ -29,7 +29,7 @@
 
 // Create 2nd instance of CDC Ports.
 #ifdef ARDUINO_ARCH_ESP32
-  #error "Currnetly multiple CDCs on ESP32-Sx is not yet supported. An PR to update core/esp32/USBCDC and/or pre-built libusb are needed."
+  #error "Currently multiple CDCs on ESP32-Sx is not yet supported. An PR to update core/esp32/USBCDC and/or pre-built libusb are needed."
   // for ESP32, we need to specify instance number when declaring object
   Adafruit_USBD_CDC USBSer1(1);
 #else