component/liburing: adapt version depending on kernel version

component/liburing/buildout.cfg

@@ -7,3 +7,12 @@ recipe = slapos.recipe.cmmi
 shared = true
 url = https://github.com/axboe/liburing/archive/refs/tags/liburing-2.3.tar.gz
 md5sum = 2e8c3c23795415475654346484f5c4b8
+
+# liburing 2.3 needs at least kernel 4.14 because it uses SO_ZEROCOPY
+# see https://github.com/axboe/liburing/blob/liburing-2.3/CHANGELOG#L13
+# see https://kernelnewbies.org/Linux_4.14#Zero-copy_from_user_memory_to_sockets
+[liburing:[int(q) for q in platform.release().split("-")[0].split(".")]<[4,14,0]]
+recipe = slapos.recipe.cmmi
+shared = true
+url = https://github.com/axboe/liburing/archive/refs/tags/liburing-2.2.tar.gz
+md5sum = 9075595460c86646a7239e3110ec0dd5