Configure: Allow disabling of digest-sign operations #2

Job	Run time
whitespace-check	0s
coverity-test	0s
multi-arch (ubuntu-20.04.arm32v7, 3.0.x, 4.0)	22m 5s
build-test (ubuntu-18.04, 3.0.x, 4.0, gcc)	2m 15s
build-test (ubuntu-18.04, 3.0.x, 4.0, clang)	2m 45s
build-test (ubuntu-20.04, 3.0.x, 4.0, gcc)	2m 16s
build-test (ubuntu-20.04, 3.0.x, 4.0, clang)	2m 37s
build-test (fedora-32, 3.0.x, 4.0, gcc)	2m 11s
build-test (fedora-32, 3.0.x, 4.0, clang)	2m 36s
build-test (opensuse-leap, 3.0.x, 4.0, gcc)	2m 21s
build-test (opensuse-leap, 3.0.x, 4.0, clang)	2m 45s
	41m 51s

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