[teamshow] Remove 't' from argument when calling docker exec

[bingwang-ms]

- What I did
teamshow reads teams raw data by running docker exec -it xxx. However, the 't' may lead to error when called without a tty. This commit fix the issue.
- How I did it
Remove 't' from argument when calling docker exec.
- How to verify it
Verified on Arista 7260.
before update:

ssh [email protected] "SONIC_CLI_IFACE_MODE=alias sudo show interfaces portchannel" 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol    Ports
-----  ---------------  ----------  -------
 0001  PortChannel0001  N/A
 0002  PortChannel0002  N/A
 0003  PortChannel0003  N/A
 0004  PortChannel0004  N/A

We can see that the Protocols and Ports are invalid.
after update:

ssh -t [email protected] "SONIC_CLI_IFACE_MODE=alias sudo show interfaces portchannel"
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports
-----  ---------------  -----------  ---------------------------
 0001  PortChannel0001  LACP(A)(Up)  Ethernet14/1(S) Ethernet13/1(S)
 0002  PortChannel0002  LACP(A)(Up)  Ethernet16/1(S) Ethernet15/1(S)
 0003  PortChannel0003  LACP(A)(Up)  Ethernet17/1(S) Ethernet18/1(S)
 0004  PortChannel0004  LACP(A)(Up)  Ethernet20/1(S) Ethernet19/1(S)

- Previous command output (if the output of a command-line utility has changed)
N/A
- New command output (if the output of a command-line utility has changed)
N/A