Allow another exception

Author: coke

t/17-space-after-comma.rakutest

@@ -30,6 +30,7 @@ sub test-it(Str $output, Str $file) {
         my $line = $line-orig;
 
         # ignore these cases already in docs/ that don't strictly follow rule
+        $line ~~ s:g/ "Z,," //;
         $line ~~ s:g/ "','" //;
         $line ~~ s:g/ '","' //;
         $line ~~ s:g/ << 'a,a,a' >> //;