fix ‘line’ option in ‘split’ block for Windows files

thanks, @brianharvey!

history.txt

@@ -2330,3 +2330,4 @@ ______
 * GUI: Set Default Save location to Cloud on load, thanks, @cycomachead!
 * GUI: Updated the “About” Dialog with a mention of support from CDG (SAP Labs)
 * BYOB: Percent sign fix for block labels, thanks, @natashasandy!
+* Threads: fix ‘line’ option in ‘split’ block for Windows files, thanks, @brianharvey!

threads.js

@@ -2126,7 +2126,7 @@ Process.prototype.reportTextSplit = function (string, delimiter) {
     str = (string || '').toString();
     switch (this.inputOption(delimiter)) {
     case 'line':
-        del = '\n';
+        del = '\r?\n';
         break;
     case 'tab':
         del = '\t';