Make absolutedir_secure default to blank, since most sites won't have

a Secure HTTP server.

sql/mysql/defaults.sql

@@ -599,7 +599,7 @@ INSERT INTO tzcodes (tz, off_set, description, dst_region, dst_tz, dst_off_set)
 # to have to find them when they are not in alphabetical order.
 
 INSERT INTO vars (name, value, description) VALUES ('absolutedir','http://www.example.com','Absolute base URL of site; used for creating links external to site that need a complete URL');
-INSERT INTO vars (name, value, description) VALUES ('absolutedir_secure','https://www.example.com','Absolute base URL of Secure HTTP site');
+INSERT INTO vars (name, value, description) VALUES ('absolutedir_secure','','Absolute base URL of Secure HTTP site (blank if site has no HTTPS side)');
 INSERT INTO vars (name, value, description) VALUES ('accesslog_insert_cachesize','0','Cache accesslog inserts and do this many all at once (0 to disable, if enabled, suggest value of 5 or so)');
 INSERT INTO vars (name, value, description) VALUES ('ad_max', '6', 'Maximum ad number (must be at least ad_messaging_num)');
 INSERT INTO vars (name, value, description) VALUES ('ad_messaging_num', '6', 'Which ad (env var AD_BANNER_x) is the "messaging ad"?');