Update src/Http/MindeeApiV2.php

Co-authored-by: sebastianMindee <130448732+sebastianMindee@users.noreply.github.com>

Author: ianardee

src/Http/MindeeApiV2.php

@@ -311,16 +311,16 @@ private function documentEnqueuePost(
             $postFields['file'] = $inputSource->fileObject;
         }
 
-        if ($params->rawText != null) {
+        if (isset($params->rawText)) {
             $postFields['raw_text'] = strtolower($params->rawText);
         }
-        if ($params->polygon != null) {
+        if (isset($params->polygon)) {
             $postFields['polygon'] = strtolower($params->polygon);
         }
-        if ($params->confidence != null) {
+        if (isset($params->confidence)) {
             $postFields['confidence'] = strtolower($params->confidence);
         }
-        if ($params->rag != null) {
+        if (isset($params->rag)) {
             $postFields['rag'] = strtolower($params->rag);
         }