AP_Networking: Change message level from DEBUG to INFO #446

Job	Run time
build (stm32f7, chibios, 10)	18m 44s
build (stm32h7, chibios, 10)	16m 43s
build (fmuv2-plane, chibios, 10)	7m 32s
build (periph-build, chibios, 10)	24m 51s
build (iofirmware, chibios, 10)	2m 20s
build (CubeOrange-bootloader, chibios, 10)	1m 24s
build (fmuv3-bootloader, chibios, 10)	1m 23s
build (revo-bootloader, chibios, 10)	1m 21s
build (stm32h7-debug, chibios, 10)	12m 27s
build (fmuv3, chibios, 10)	21m 3s
build (revo-mini, chibios, 10)	18m 1s
build (MatekF405-Wing, chibios, 10)	17m 57s
build (CubeOrange-ODID, chibios, 10)	10m 29s
build (CubeRedPrimary-bootloader, chibios, 10)	1m 40s
build (configure-all, chibios, 10)	8m 16s
build (build-options-defaults-test, chibios, 10)	27m 19s
build (signing, chibios, 10)	14m 51s
	3h 26m 21s

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