server: unskip TestSSLEnforcement
server: unskip TestSSLEnforcement

Fixes #4663.

cockroachdb/cockroach,cuongdo/cockroach,maxlang/cockroach,veteranlu/cockroach,glycerine/cockroach,nieyy/cockroach,arjun4084346/cockroach,maxlang/cockroach,glycerine/cockroach,sunya123/cockroach,arjun4084346/cockroach,maxlang/cockroach,bg451/cockroach,arjun4084346/cockroach,nieyy/cockroach,paperstreet/cockroach,veteranlu/cockroach,arjun4084346/cockroach,nieyy/cockroach,cockroachdb/cockroach,petermattis/cockroach,cuongdo/cockroach,cuongdo/cockroach,maxlang/cockroach,vivekmenezes/cockroach,cuongdo/cockroach,paperstreet/cockroach,sunya123/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,vivekmenezes/cockroach,nieyy/cockroach,cuongdo/cockroach,petermattis/cockroach,sunya123/cockroach,bg451/cockroach,cockroachdb/cockroach,vivekmenezes/cockroach,vivekmenezes/cockroach,vivekmenezes/cockroach,vivekmenezes/cockroach,nieyy/cockroach,veteranlu/cockroach,paperstreet/cockroach,arjun4084346/cockroach,petermattis/cockroach,glycerine/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,bg451/cockroach,bg451/cockroach,cuongdo/cockroach,maxlang/cockroach,petermattis/cockroach,arjun4084346/cockroach,sunya123/cockroach,paperstreet/cockroach,paperstreet/cockroach,glycerine/cockroach,cockroachdb/cockroach,veteranlu/cockroach,cockroachdb/cockroach,cockroachdb/cockroach,nieyy/cockroach,maxlang/cockroach,maxlang/cockroach,arjun4084346/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,nieyy/cockroach,vaibhavarora/cockroach,glycerine/cockroach,glycerine/cockroach,petermattis/cockroach,sunya123/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,glycerine/cockroach,sunya123/cockroach,vivekmenezes/cockroach,sunya123/cockroach,petermattis/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,nieyy/cockroach,paperstreet/cockroach,veteranlu/cockroach,bg451/cockroach,vivekmenezes/cockroach,paperstreet/cockroach,petermattis/cockroach,cockroachdb/cockroach,bg451/cockroach,petermattis/cockroach,cuongdo/cockroach,bg451/cockroach,cuongdo/cockroach,maxlang/cockroach,cockroachdb/cockroach,sunya123/cockroach,glycerine/cockroach,arjun4084346/cockroach