Revert "change file.url to from a varchar(255) to varchar(2047)"

This reverts commit 002cc755b2.

mysql doesn't allow varchar > 255 chars
reverting until have a working solution

db/laconica.sql

@@ -433,7 +433,7 @@ create table group_inbox (
 create table file (
 
     id integer primary key auto_increment,
-    url varchar(2047) comment 'destination URL after following redirections',
+    url varchar(255) comment 'destination URL after following redirections',
     mimetype varchar(50) comment 'mime type of resource',
     size integer comment 'size of resource when available',
     title varchar(255) comment 'title of resource when available',

db/laconica_pg.sql

@@ -450,7 +450,7 @@ create index group_inbox_created_idx on group_inbox using btree(created);
 create sequence file_seq;
 create table file (
     id bigint default nextval('file_seq') primary key /* comment 'unique identifier' */,
-    url varchar(2047) unique, 
+    url varchar(255) unique, 
     mimetype varchar(50), 
     size integer, 
     title varchar(255),