libsearpc: use commit hash to select upstream version instead of (presumably) rolling release tag

Signed-off-by: Gergely Kiss <mail.gery@gmail.com>
Tested-by: Gergely Kiss <mail.gery@gmail.com>
libsearpc: use commit hash from upstream within the version instead of a (probably) rolling release tag

Signed-off-by: Gergely Kiss <mail.gery@gmail.com>
Tested-by: Gergely Kiss <mail.gery@gmail.com>