Fixed misplaced semi-colon in conditional build script

Author: blemasle

.travis.yml

@@ -16,7 +16,7 @@ before_install:
   - sudo mv arduino-$ARDUINO_IDE_VERSION /usr/local/share/arduino
   - sudo ln -s /usr/local/share/arduino/arduino /usr/local/bin/arduino
   - arduino --pref boardsmanager.additional.urls=https://dl.espressif.com/dl/package_esp32_index.json --save-prefs
-  - if $ESP32 then; arduino --install-boards esp32:esp32:$ARDUINO_ESP32_VERSION; fi
+  - if $ESP32; then arduino --install-boards esp32:esp32:$ARDUINO_ESP32_VERSION; fi
 install:
  - ln -s $PWD /usr/local/share/arduino/libraries/$LIBRARY_NAME
  - arduino --install-library "ArduinoLog"