Fix data race #315

Job	Run time
lint	55s
CMake-Linux	4m 23s
Native-x64-Linux	38m 9s
CMake-Linux-latest	4m 8s
Depends-ARM 32-bit	1m 39s
Native-x64-Linux-latest	34m 45s
CMake-macOS	18m 43s
Depends-AARCH64	1m 50s
Native-x64-macOS	1h 16m 14s
CMake-macOS-latest	13m 26s
Depends-Win64	1m 52s
Native-x64-macOS-latest	1h 0m 13s
Depends-32-bit + dash	2m 1s
Depends-x86_64 Linux	1m 45s
Depends-macOS 10.12	1m 42s
ARM 32-bit [GOAL:install] [no unit or functional tests]	21m 27s
AARCH64 [GOAL:install] [no unit or functional tests]	22m 22s
Win64 [GOAL:deploy] [no unit or functional tests]	25m 13s
x86_64 Linux [GOAL:install]	34m 36s
x86_64 Linux [GOAL:install] [no GUI, no unit tests, only functional tests on legacy pre-HD wallets]	21m 35s
macOS 10.12 [GOAL:deploy] [no unit or functional tests]	19m 0s
	6h 45m 58s

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