Adding extra check if def macros are not actually present in the source

jsm.inc.php

@@ -523,7 +523,12 @@ class JSM
 
   private function _extractScriptDefs(string $file, string $txt) : string
   {
-    if(strpos($txt, 'def') === false)
+    $strpos = strpos($txt, 'def');
+    if($strpos === false)
+      return $txt;
+
+    //let's extra check if newline symbols preceed 'def'
+    if($strpos > 0 && !($txt[$strpos-1] === "\n" || $txt[$strpos-1] === "\r"))
       return $txt;
 
     //NOTE: make it more robust