Vault autocomplete is choking on secret mounts depper than 1 level

[tonglil]

Describe the bug
The vault autocomplete does not seem to be able to autocomplete when secrets are mounted with a / in the path, but is not an actual "path".

I'm not fluent enough to make any changes in what seems to be the source here.

To Reproduce
Setup:

$ vault -autocomplete-install

$ vault secrets enable -path=org1/team-a/kv1 kv
$ vault secrets enable -path=org1/team-a/kv2 kv

$ vault secrets enable -path=org1/team-b/kv1 kv
$ vault secrets enable -path=org1/team-b/kv2 kv

$ vault secrets enable -path=org2/team-a/kv1 kv
$ vault secrets enable -path=org2/team-a/kv2 kv

$ vault secrets enable -path=org2/team-b/kv1 kv
$ vault secrets enable -path=org2/team-b/kv2 kv

$ vault kv put org1/team-a/kv1/new/inside value=hi
$ vault kv put org1/team-a/kv1/more/inside value=hi

Expected behavior
Working:

$ vault list or<TAB>
org1/team-a/kv1/  org1/team-a/kv2/  org1/team-b/kv1/  org1/team-b/kv2/  org2/team-a/kv1/  org2/team-a/kv2/  org2/team-b/kv1/  org2/team-b/kv2/
$ vault list org1<TAB>
org1/team-a/kv1/  org1/team-a/kv2/  org1/team-b/kv1/  org1/team-b/kv2/  
$ vault list org1/team-a/kv1/
org1/team-a/kv1/more/  org1/team-a/kv1/new/   

Not working:

$ vault list org1/<TAB>
$ vault list org1/team<TAB>
$ vault list org1/team-a<TAB>
$ vault list org1/team-a/<TAB>
$ vault list org1/team-a/k<TAB>
$ vault list org1/team-a/kv1<TAB>

Environment:

vault status
Key             Value
---             -----
Seal Type       shamir
Initialized     true
Sealed          false
Total Shares    1
Threshold       1
Version         1.2.3
Cluster Name    vault-cluster-9195e478
Cluster ID      f9e1c1ca-d571-1db8-53be-c9f503b7168c
HA Enabled      false

vault version
Vault v1.2.3 ('c14bd9a2b1d2c20f15b9f93f5c2d487507bb8a2f+CHANGES')

sw_vers
ProductName:	Mac OS X
ProductVersion:	10.14.6
BuildVersion:	18G1012

Vault server configuration file(s): none

Additional context
Add any other context about the problem here.