AP_DroneCAN_DNA_Server : adding delay while logging 'CAND' #912

Job	Run time
build (stm32f7, chibios, 10)	8m 11s
build (stm32h7, chibios, 10)	7m 21s
build (fmuv2-plane, chibios, 10)	5m 11s
build (periph-build, chibios, 10)	9m 38s
build (iofirmware, chibios, 10)	3m 58s
build (CubeOrange-bootloader, chibios, 10)	3m 7s
build (fmuv3-bootloader, chibios, 10)	3m 2s
build (revo-bootloader, chibios, 10)	3m 11s
build (stm32h7-debug, chibios, 10)	5m 22s
build (fmuv3, chibios, 10)	10m 27s
build (revo-mini, chibios, 10)	8m 18s
build (MatekF405-Wing, chibios, 10)	9m 8s
build (CubeOrange-ODID, chibios, 10)	5m 54s
build (CubeRedPrimary-bootloader, chibios, 10)	3m 21s
build (configure-all, chibios, 10)	11m 51s
build (build-options-defaults-test, chibios, 10)	11m 15s
build (signing, chibios, 10)	6m 7s
build (CubeOrange-PPP, chibios, 10)	5m 15s
build (CubeOrange-SOHW, chibios, 10)	5m 30s
build (Pixhawk6X-PPPGW, chibios, 10)	3m 50s
	2h 9m 57s

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