Initialise box in rest.c #7381

Job	Run time
pre-ci	6s
master-self-ubuntu20-linux-gcc-lean	6m 15s
master-self-ubuntu20-linux-gcc	7m 34s
master-self-ubuntu20-linux-gcc-O2-g3	6m 59s
master-self-ubuntu20-linux-gcc-ndebug	6m 36s
master-self-ubuntu20-linux-clang-lean	8m 51s
master-self-ubuntu20-linux-clang	8m 52s
master-self-ubuntu20-linux-clang-O2-g3	9m 25s
master-self-ubuntu20-linux-clang-ndebug	9m 25s
master-self-ubuntu20-linux-clang-altlibs	8m 26s
master-self-ubuntu20-linux-fuzzer	11m 43s
Merge preflight	0s
Merge into upstream	0s
	1h 24m 12s

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