Move sysctls to correct API version

Commit 067b510dfc5b90a1d7712c89e857b6dafb184f24 move the
sysctls feature to the right API version, but
missed this one.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/reference/api/docker_remote_api_v1.21.md

@@ -200,7 +200,6 @@ Create a container
              "RestartPolicy": { "Name": "", "MaximumRetryCount": 0 },
              "NetworkMode": "bridge",
              "Devices": [],
-             "Sysctls": { "net.ipv4.ip_forward": "1" },
              "Ulimits": [{}],
              "LogConfig": { "Type": "json-file", "Config": {} },
              "SecurityOpt": [],

docs/reference/api/docker_remote_api_v1.24.md

@@ -327,6 +327,7 @@ Create a container
              "RestartPolicy": { "Name": "", "MaximumRetryCount": 0 },
              "NetworkMode": "bridge",
              "Devices": [],
+             "Sysctls": { "net.ipv4.ip_forward": "1" },
              "Ulimits": [{}],
              "LogConfig": { "Type": "json-file", "Config": {} },
              "SecurityOpt": [],