fix checkActionBlock(): fix off-by-one mistake when this one reports …

…about a piece of action code which "does not compile": lexer and parser line tracking yylloc info starts counting at line ONE(1) instead of ZERO(0) hence we do NOT need to compensate when bumping down the action code before parsing/validating it in here.

packages/helpers-lib/parse-code-chunk-to-AST.js

@@ -87,7 +87,7 @@ function checkActionBlock(src, yylloc) {
     // make sure reasonable line numbers, etc. are reported in any
     // potential parse errors by pushing the source code down:
     if (yylloc && yylloc.first_line > 0) {
-        var cnt = yylloc.first_line + 1;
+        var cnt = yylloc.first_line;
         var lines = new Array(cnt);
         src = lines.join('\n') + src;
     }