MDL-12720 removing confusing/not implemented CONTEXT_PERSONAL; merged from MOODLE_19_STABLE

lib/db/upgrade.php

@@ -2658,6 +2658,19 @@ function xmldb_main_upgrade($oldversion=0) {
         upgrade_main_savepoint($result, 2007101505);
     }
 
+    if ($result && $oldversion < 2007101506) {
+
+    /// CONTEXT_PERSONAL was never implemented - removing
+        $sql = "DELETE
+                  FROM {$CFG->prefix}context
+                 WHERE contextlevel=20";
+ 
+        execute_sql($sql);
+
+    /// Main savepoint reached
+        upgrade_main_savepoint($result, 2007101506);
+    }
+
     return $result;
 }
 

version.php

@@ -6,7 +6,7 @@
 // This is compared against the values stored in the database to determine
 // whether upgrades should be performed (see lib/db/*.php)
 
-    $version = 2007101505;  // YYYYMMDD = date
+    $version = 2007101506;  // YYYYMMDD = date
                             //       XY = increments within a single day
 
     $release = '2.0 dev';   // Human-friendly version name