Rename regex field from domain to filter because this described better what it is

Signed-off-by: DL6ER <dl6er@dl6er.de>

advanced/Templates/gravity.db.sql

@@ -1,6 +1,6 @@
 CREATE TABLE whitelist (domain TEXT UNIQUE NOT NULL, enabled BOOLEAN DEFAULT 1, comment TEXT, dateadded DATETIME);
 CREATE TABLE blacklist (domain TEXT UNIQUE NOT NULL, enabled BOOLEAN DEFAULT 1, comment TEXT, dateadded DATETIME);
-CREATE TABLE regex     (domain TEXT UNIQUE NOT NULL, enabled BOOLEAN DEFAULT 1, comment TEXT, dateadded DATETIME);
+CREATE TABLE regex     (filter TEXT UNIQUE NOT NULL, enabled BOOLEAN DEFAULT 1, comment TEXT, dateadded DATETIME);
 CREATE TABLE gravity   (domain TEXT UNIQUE NOT NULL);
 
 CREATE VIEW vw_gravity AS SELECT DISTINCT a.domain