Merge pull request #17295 from nextcloud/backport/17286/stable17

[stable17] Correctly detect the mimetype from uploads

Author: rullzer

apps/workflowengine/lib/Check/FileMimeType.php

@@ -113,7 +113,7 @@ protected function getActualValue() {
 			$files = $this->request->getUploadedFile('files');
 			if (isset($files['type'][0])) {
 				$mimeType = $files['type'][0];
-				if ($this->mimeType === 'application/octet-stream') {
+				if ($mimeType === 'application/octet-stream') {
 					// Maybe not...
 					$mimeTypeTest = $this->mimeTypeDetector->detectPath($files['name'][0]);
 					if ($mimeTypeTest !== 'application/octet-stream' && $mimeTypeTest !== false) {