Fix (global) db leakage, by making db local.

Thanks to mickhansen for the fix.

lib/dialects/sqlite/connector-manager.js

@@ -18,6 +18,7 @@ module.exports = (function() {
   ConnectorManager.prototype.connect = function() {
     var emitter = new (require('events').EventEmitter)()
       , self = this
+      , db
 
     this.database = db = new sqlite3.Database(self.sequelize.options.storage || ':memory:', function(err) {
       if (err) {