[teamshow]: Does not display proper output if run by regular user

[jleveque]

If teamshow is run by a regular user (i.e., not admin or root), the "Protocol" column only displays "N/A" for all portchannels, and the "Ports" column is empty.

However, if run as admin or root, the output is correct.

UPDATE: This is caused by the fact that /usr/bin/teamdctl on the base image tries to run teamdctl inside the teamd docker, but regular users do not have permissions to run docker exec.