[BT] Move keepalive init to init callback #374

Job	Run time
build (hw1, 3do)	3m 58s
build (hw1, cdi)	4m 3s
build (hw1, dreamcast)	4m 1s
build (hw1, gamecube)	4m 21s
build (hw1, gbahd)	5m 13s
build (hw1, genesis)	4m 15s
build (hw1, jaguar)	3m 51s
build (hw1, jvs_arcade)	3m 57s
build (hw1, n64)	3m 49s
build (hw1, nes)	3m 52s
build (hw1, parallel_1p)	4m 3s
build (hw1, parallel_1p_3v3)	4m 10s
build (hw1, parallel_2p)	4m 11s
build (hw1, parallel_2p_3v3)	3m 57s
build (hw1, pc_engine)	3m 37s
build (hw1, pcfx)	3m 37s
build (hw1, playstation)	4m 40s
build (hw1, saturn)	5m 25s
build (hw1, snes)	4m 17s
build (hw1, universal)	3m 29s
build (hw1, virtualboy)	3m 32s
build (hw1, wii_extension)	4m 7s
build (hw2, 3do)	3m 27s
build (hw2, cdi)	3m 55s
build (hw2, dreamcast)	3m 53s
build (hw2, gamecube)	3m 21s
build (hw2, gbahd)	3m 26s
build (hw2, genesis)	3m 28s
build (hw2, jaguar)	3m 48s
build (hw2, jvs_arcade)	3m 26s
build (hw2, n64)	3m 50s
build (hw2, nes)	3m 32s
build (hw2, parallel_1p)	3m 20s
build (hw2, parallel_1p_3v3)	3m 14s
build (hw2, parallel_2p)	3m 31s
build (hw2, parallel_2p_3v3)	4m 0s
build (hw2, pc_engine)	3m 38s
build (hw2, pcfx)	3m 24s
build (hw2, playstation)	3m 41s
build (hw2, saturn)	3m 27s
build (hw2, snes)	4m 8s
build (hw2, universal)	3m 26s
build (hw2, virtualboy)	3m 41s
build (hw2, wii_extension)	4m 23s
build (dbg, pad_test)	4m 30s
build (dbg, qemu)	3m 59s
build (dbg, qemu_bt_trace_replay)	4m 1s
build (dbg, qemu_bt_trace_replay_test)	3m 59s
	3h 6m 53s

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