Fix build warnings and errors #29

Job	Run time
esp8266 (examples/simpleServer/simpleServer.ino)	1m 23s
esp32 (examples/simpleServer/simpleServer.ino)	50s
esp32 (examples/customOptions/customOptions.ino)	41s
esp8266 (examples/customOptions/customOptions.ino)	1m 15s
esp32 (examples/customHTML/customHTML.ino)	41s
esp8266 (examples/customHTML/customHTML.ino)	1m 7s
esp32 (examples/gpio_list/gpio_list.ino)	41s
esp8266 (examples/gpio_list/gpio_list.ino)	1m 5s
esp32 (examples/handleFormData/handleFormData.ino)	49s
esp32 (examples/highcharts/highcharts.ino)	41s
esp8266 (examples/handleFormData/handleFormData.ino)	1m 20s
esp32 (examples/remoteOTA/remoteOTA.ino)	50s
esp8266 (examples/highcharts/highcharts.ino)	1m 5s
esp32 (examples/withWebSocket/withWebSocket.ino)	56s
esp8266 (examples/remoteOTA/remoteOTA.ino)	1m 9s
esp32 (examples/esp32-cam/esp32-cam.ino)	41s
esp8266 (examples/withWebSocket/withWebSocket.ino)	1m 10s
	16m 24s

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