lua-nucleo/test/cases/0190-table-utils: fix compatibility with LuaJIT 2

[rafis]

Suite test tslice_table_contains_nil
test/cases/0190-table-utils.lua:1809: ensure_tequals failed: input table contains nil: bad actual value at key 3': gotnil', expected `3'
stack traceback:
[C]: in function 'error'
lua-nucleo/ensure.lua:107: in function 'ensure_tequals'
test/cases/0190-table-utils.lua:1809: in function 'fn'
lua-nucleo/suite.lua:167: in function <lua-nucleo/suite.lua:167>
[C]: in function 'xpcall'
lua-nucleo/suite.lua:167: in function 'run'
lua-nucleo/suite.lua:556: in function <lua-nucleo/suite.lua:552>
[C]: in function 'xpcall'
lua-nucleo/suite.lua:551: in function 'run_test'
lua-nucleo/suite.lua:600: in function 'run_tests'
test/test.lua:134: in main chunk
[C]: at 0x00404980
ERR
#2390