When using advanced syntax for setting config and secret values, default
the target value to the source value when the user does not specify a
target.
Signed-off-by: Nick Adcock <nick.adcock@docker.com>
Allow the use of the advanced source=x syntax for config and secret values when there is no comma
Before this change the following would fail with config not found:
docker service create --name hello1 --config source=myconfig nginx:alpine
And the following would fail with secret not found:
docker service create --name hello2 --secret source=mysecret nginx:alpine
Signed-off-by: Nick Adcock <nick.adcock@docker.com>