MDL-52105 enrol_self: Fix wrong holdkey cap restriction for manager

This commit add an upgrade step to remove wrong CAP_PROHIBIT on enrol/self:holdkey for manager role.
Also remove the restriction from the self enrolment access file.

enrol/self/db/access.php

@@ -52,9 +52,6 @@ $capabilities = array(
 
         'captype' => 'write',
         'contextlevel' => CONTEXT_COURSE,
-        'archetypes' => array(
-            'manager' => CAP_PROHIBIT,
-        )
     ),
 
     /* Voluntarily unenrol self from course - watch out for data loss. */

enrol/self/db/upgrade.php

@@ -39,5 +39,24 @@ function xmldb_enrol_self_upgrade($oldversion) {
     // Moodle v3.1.0 release upgrade line.
     // Put any upgrade step following this.
 
+    // Moodle v3.2.0 release upgrade line.
+    // Put any upgrade step following this.
+
+    if ($oldversion < 2016052301) {
+        global $DB;
+        // Get roles with manager archetype.
+        $managerroles = get_archetype_roles('manager');
+        if (!empty($managerroles)) {
+            // Remove wrong CAP_PROHIBIT from self:holdkey.
+            foreach ($managerroles as $role) {
+                $DB->execute("DELETE
+                                FROM {role_capabilities}
+                               WHERE roleid = ? AND capability = ? AND permission = ?",
+                        array($role->id, 'enrol/self:holdkey', CAP_PROHIBIT));
+            }
+        }
+        upgrade_mod_savepoint(true, 2016052301, 'enrol_self');
+    }
+
     return true;
 }

enrol/self/version.php

@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2016052300;        // The current plugin version (Date: YYYYMMDDXX)
+$plugin->version   = 2016052301;        // The current plugin version (Date: YYYYMMDDXX)
 $plugin->requires  = 2016051900;        // Requires this Moodle version
 $plugin->component = 'enrol_self';      // Full name of the plugin (used for diagnostics)
 $plugin->cron      = 600;