Update 2016_01_04_173148_create_admin_tables.php

有时候url上要带一些传参，多个参数的时候存在存不下的情况

Author: jxlwqq

database/migrations/2016_01_04_173148_create_admin_tables.php

@@ -53,7 +53,7 @@ public function up()
             $table->integer('order')->default(0);
             $table->string('title', 50);
             $table->string('icon', 50);
-            $table->string('uri', 50)->nullable();
+            $table->string('uri')->nullable();
             $table->string('permission')->nullable();
 
             $table->timestamps();