set max argument length to 4000

db_structure.xml

@@ -979,7 +979,7 @@
 				<type>text</type>
 				<default></default>
 				<notnull>true</notnull>
-				<length>2048</length>
+				<length>4000</length>
 			</field>
 
 			<field>

lib/private/backgroundjob/joblist.php

@@ -57,7 +57,7 @@ class JobList implements IJobList {
 				$class = $job;
 			}
 			$argument = json_encode($argument);
-			if (strlen($argument) > 2048) {
+			if (strlen($argument) > 4000) {
 				throw new \InvalidArgumentException('Background job arguments cant exceed 2048 characters (json encoded');
 			}
 			$query = $this->conn->prepare('INSERT INTO `*PREFIX*jobs`(`class`, `argument`, `last_run`) VALUES(?, ?, 0)');