app/fax/app_defaults.php: (#2031)

+ fix: duplicate check only within same default_setting_category.  This fixes the bug where "keep_local" for fax wasn't being created because there was a "keep_local" for voicemail.  Without this fix you will get a lua error due to the field not being set and nothing shows up in the sent faxes log.

fax/fax_log_view.php:
+ fix: back button text is missing.  Copied correct localized text code from another fax page that worked.

app/fax/app_config.php
+ fix: date field is now timestamp for postgres+mysql.  This fixes the listing only showing the date, not the time as well.

Note: app->defaults doesn't change field types.  Existing installs will have to manually update the field type e.g. for postgres:

sudo -sHu postgres
\d fusionpbx
alter table v_fax_logs alter column fax_date type timestamp without time zone;
\q

app/fax/app_defaults.php

@@ -158,7 +158,7 @@ if ($domains_processed == 1) {
 		$x++;
 
 	//get an array of the default settings
-		$sql = "select * from v_default_settings ";
+		$sql = "select * from v_default_settings where default_setting_category = 'fax'";
 		$prep_statement = $db->prepare($sql);
 		$prep_statement->execute();
 		$default_settings = $prep_statement->fetchAll(PDO::FETCH_NAMED);