fix empty first line

dist/index.js

@@ -180,7 +180,7 @@ function writeFeedToFile(feedUrl, existingFileLocation, tempFileLocation) {
         suppressEmptyNode: true
     };
     const builder = new fast_xml_parser_1.XMLBuilder(xmlBuilderOptions);
-    const output = builder.build(xmlSource);
+    const output = builder.build(xmlSource).trim();
     core.debug(output);
     fs.writeFileSync(tempFileLocation, output);
 }

src/authutil.ts

@@ -193,7 +193,7 @@ function writeFeedToFile(
 
   const builder = new XMLBuilder(xmlBuilderOptions);
 
-  const output = builder.build(xmlSource);
+  const output = builder.build(xmlSource).trim();
 
   core.debug(output);