General: Trim the input data in maybe_unserialize(), for consistency with is_serialized().

Props pbearne, mikeschroder.
Fixes #36416.

git-svn-id: https://develop.svn.wordpress.org/trunk@47454 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/functions.php

@@ -616,7 +616,7 @@ function maybe_serialize( $data ) {
  */
 function maybe_unserialize( $data ) {
 	if ( is_serialized( $data ) ) { // Don't attempt to unserialize data that wasn't serialized going in.
-		return @unserialize( $data );
+		return @unserialize( trim( $data ) );
 	}
 
 	return $data;