Remove devstack-plugin-container from gate_hook
Remove devstack-plugin-container from gate_hook

Since we have add devstack-plugin-container to jenkins jobs in [0],
So we need remove it from gate_hook.

[0]: I0bbd654499ec3a916766352f0cda64e78ae6109d

Change-Id: I1c3272b16065e85793748b4c201ab68408c715e2

stackforge/solum,openstack/solum,stackforge/solum,openstack/solum