Bug 1660237: Adding log debug message when upgrading

As per convention when adding an upgrade block

behatnotneeded

Change-Id: Ifb33f6e588093d800ea983347ba888a9c5ed18d2
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/lib/db/upgrade.php

@@ -5416,6 +5416,7 @@ function xmldb_core_upgrade($oldversion=0) {
     }
 
     if ($oldversion < 2017103100) {
+        log_debug('Remove MaharaDroid configurations');
         // remove allowmobileuploads from config, used only by old mobile api
         delete_records('config','field','allowmobileuploads');
         // remove mobileuploadtoken from account settings, used only by old mobile api