MDL-51698 upgrade: bump version to newer than rewritten one

Some integration.git based sites can have 2015120801 version,
now rewritten. This commit ensures everybody goes forward to
2015120803.

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2015120800.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2015120803.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.