(xmlsec-nss) Ensure we search NSS database even if local xmlsec certs list is empty #1364

Job	Run time
check-osx	4m 21s
check-ubuntu	3m 33s
check-mingw (MINGW64, x86_64)	15m 32s
check-ubuntu (--enable-legacy-features --enable-ftp --enable-http)	4m 54s
check-mingw (MINGW64, x86_64, --enable-static --enable-static-linking --enable-unicode=no --witho...	8m 36s
check-ubuntu (--enable-static --enable-static-linking --disable-openssl3-engines --without-nss --...	3m 7s
check-ubuntu-openssl-111	1m 31s
check-ubuntu (--enable-static --enable-static-linking --without-openssl --without-nss --without-g...	4m 36s
check-ubuntu-openssl-111 (--enable-static --enable-static-linking --without-nss --without-gnutls ...	1m 4s
check-msvc (mscng, unicode=yes with-dl=yes)	2m 24s
check-msvc (mscng, unicode=no with-dl=no static=yes legacy-features=yes)	3m 3s
check-msvc (mscrypto)	2m 23s
check-msvc (mscrypto, unicode=no with-dl=no static=yes legacy-features=yes)	1m 58s
check-msvc (openssl-300)	6m 22s
check-msvc (openssl-300, unicode=no with-dl=no static=yes)	6m 34s
	1h 9m 58s

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