crypto: fix missing nullptr check on RSA_new() #3499

Job	Run time
Build slim tarball	2m 50s
aarch64-linux: with shared libraries	19m 30s
x86_64-linux: with shared libraries	22m 58s
aarch64-darwin: with shared libraries	25m 19s
x86_64-darwin: with shared libraries	42m 55s
	1h 53m 32s

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