[acl-loader] Fix bugs in acl-loader

[daall]

• Fix issue where protocol == 0 would be ignored
• Emit warning if --table_name not found in Config DB

Signed-off-by: Danny Allen daall@microsoft.com

- What I did/How I did it
I fixed a bug in acl-loader where rules with protocol=0 would have the protocol field ignored due to python's implicit boolean conversion. I fixed this by explicitly adding the == 0 check to the ip protocol field.

I also fixed/added a warning when the provided --table_name can't be found in Config DB. Previously this case would fail silently, now the user will receive a warning to point them in the right direction.

- How to verify it
Run acl-loader with a non-existent --table_name:

admin@sonic:~$ sudo acl-loader update full test.json --table_name yeehaw
Warning: Table "yeehaw" not found

Run acl-loader with a rule that includes "protocol": 0:

admin@sonic:~$ sudo acl-loader update full test.json --session_name test
admin@sonic:~$ show acl rule
Table       Rule      Priority  Action                Match
----------  ------  ----------  --------------------  --------------
EVERFLOW    RULE_1        9999  MIRROR INGRESS: test  IP_PROTOCOL: 0

- Previous command output (if the output of a command-line utility has changed)

- New command output (if the output of a command-line utility has changed)

[daall]

retest this please

[daall]

retest this please