Fixups for CentOS 7 which is now EOL #384

Job	Run time
pre-ci	5s
v3.2.x-gh-ubuntu20-linux-gcc-lean	2m 41s
v3.2.x-gh-ubuntu20-linux-gcc	2m 30s
v3.2.x-gh-ubuntu20-linux-gcc-reproducible	2m 30s
v3.2.x-gh-ubuntu20-linux-gcc-O2-g3	2m 39s
v3.2.x-gh-ubuntu20-linux-clang-lean	5m 11s
v3.2.x-gh-ubuntu20-linux-clang	5m 36s
v3.2.x-gh-ubuntu20-linux-clang-altlibs	5m 51s
v3.2.x-gh-ubuntu20-linux-clang-reproducible	5m 41s
v3.2.x-gh-ubuntu20-linux-clang-sanitizer	6m 54s
v3.2.x-gh-ubuntu20-linux-clang-O2-g3	5m 43s
Merge preflight	1s
Merge into upstream	0s
	45m 22s

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