Fix misnamed unique constraint

db/core.php

@@ -650,7 +650,7 @@ $schema['user_group'] = array(
     ),
     'primary key' => array('id'),
     'unique keys' => array(
-        'user_uri_key' => array('uri'),
+        'user_group_uri_key' => array('uri'),
     ),
     'foreign keys' => array(
         'user_group_design_id_fkey' => array('design', array('design_id' => 'id')),

lib/schema.php

@@ -653,11 +653,7 @@ class Schema
 
     function quoteValue($val)
     {
-        if (is_int($val) || is_float($val) || is_double($val)) {
-            return strval($val);
-        } else {
-            return '"' . $this->conn->escapeSimple($val) . '"';
-        }
+        return $this->conn->quoteSmart($val);
     }
 
     /**