Without this commit etcd returns the following error message when
setting values on directories:
{
"errorCode":102,
"message":"Not a file",
"cause":"/postgres",
"index":2
}
While the above error message is accurate it's not very descriptive.
This commit adds a new error code/message which better describes why the
write operation failed. etcd now returns the following:
{
"errorCode":109,
"message":"Cannot set value on directory",
"cause":"/postgres",
"index":2
}