CLEANUP: tcp-rules: Fix a typo in error messages about expect-netscaler-cip

CLEANUP: tcp-rules: Fix a typo in error messages about expect-netscaler-cip

It was misspelled (expect-netscaler-ip instead of expect-netscaler-cip). 2
commits are concerned :

 * db67b0ed7 MINOR: tcp-rules: suggest approaching action names on mismatch
 * 72d012fbd CLEANUP: tcp-rules: add missing actions in the tcp-request error message

The first one will not be backported, but the second one was backported as
far as 1.8. Thus this one may also be backported, but only the 2nd part
about the list of accepted keywords.