Update GXP2170 Template and Readme (#3005)

* Update README.txt

Corrected paths in readme

* Update {$mac}.xml

Updated template to support the latest Grandstream firmware - v1.0.9.26
Fixed some broken and incomplete entries.  Cleaned up formatting.
Corrected values to match entries in Default Settings (gs_xxxx to grandstream_xxxx)

* Update app_config.php

Fixed descriptions for their correct value.
Set timezone from fixed Pacific to Auto.

* Update app_config.php

Added entries to match up with values in the provision template.

resources/templates/provision/grandstream/gxp2170/README.txt

@@ -7,7 +7,7 @@ I've added symlinks so you can download both files for upload to the phone if au
  - auto provision requires
 	nginx rewrite rules
 	provision enabled text true
-	provision granstream_config_server_path text mydomain.com/provision
+	provision granstream_config_server_path text mydomain.com/app/provision
 	# to enable phonebook contacts see below...
 
 ======================
@@ -22,15 +22,15 @@ phonebook.xml
 This provisions the phonebook button and the phone's display for incoming/outgoing calls.
 
  - requires nginx rewrite rules
-	rewrite "^.*/provision/pb([A-Fa-f0-9-]{12,17})/phonebook\.xml$" /app/provision/?mac=$1&file=phonebook.xml;
+	rewrite "^.*/provision/pb/([A-Fa-f0-9]{12})/phonebook\.xml$" /app/provision/?mac=$1&file=phonebook.xml;
 
  - requires Default Settings:
 	provision enabled text true
 	provision contact_extensions boolean false
 	provision contact_grandstream text true
-	provision granstream_phonebook_xml_server_path text mydomain.com/provision/pb  # note provision template adds {$mac} on the end
+	provision granstream_phonebook_xml_server_path text mydomain.com/app/provision/pb/  # note provision template adds {$mac} on the end
 		 handled by nginx (above).
-	provision granstream_config_server_path text mydomain.com/provision
+	provision granstream_config_server_path text mydomain.com/app/provision
 	provision granstream_phonebook_download_interval text 720
 	provision granstream_global_contact_groups text contacts_it,contacts_finance  # these are setup in Group Manager (see below).
 		 Comma seperated groups listed here will be on all phones, saving the need to add these groups to every user.