Remove line numbering from config file examples

(cherry picked from commit 31e3d1aaf7)

doc/arm/config-auth.inc.rst

@@ -101,7 +101,6 @@ The zone files are unmodified :ref:`from the base samples<base_zone_file>` but
 the :iscman:`named.conf` file has been modified as shown:
 
 .. code-block:: c
-        :linenos:
 
         // authoritative primary named.conf file
         // options clause defining the server-wide properties
@@ -186,7 +185,6 @@ not required (the zone file is obtained from the primary via zone transfer).
 The :iscman:`named.conf` file has been modified as shown:
 
 .. code-block:: c
-        :linenos:
 
         // authoritative secondary named.conf file
         // options clause defining the server-wide properties

doc/arm/config-intro.inc.rst

@@ -47,7 +47,6 @@ This file illustrates the typical format and layout style used for
 as required by the user.
 
 .. code-block:: c
-        :linenos:
 
         // base named.conf file
         // Recommended that you always maintain a change log in this file as shown here
@@ -175,7 +174,6 @@ completeness and provides for both IPv4 and IPv6 localhost resolution. The zone
 (domain) name is **localhost.**
 
 .. code-block::
-        :linenos:
 
         $TTL 3h
         localhost.  SOA      localhost.  nobody.localhost. 42  1d  12h  1w  3h
@@ -195,7 +193,6 @@ from reaching the public DNS hierarchy. The BIND 9 distribution file
 ``localhost.rev`` is shown for completeness:
 
 .. code-block::
-        :linenos:
 
         $TTL 1D
         @        IN        SOA  localhost. root.localhost. (

doc/arm/config-resolve.inc.rst

@@ -158,7 +158,6 @@ file is named ``192.168.254.rev`` and has a zone name of
 **254.168.192.in-addr.arpa**.
 
 .. code-block::
-	:linenos:
 
 	; reverse map zone file for 192.168.254.4 only
 	$TTL 2d  ; 172800 seconds
@@ -186,7 +185,6 @@ The resolver provides :ref:`recursive query support<recursive_query>` to a defin
 It is therefore a **closed** resolver and cannot be used in wider network attacks.
 
 .. code-block:: c
-        :linenos:
 
         // resolver named.conf file
         // Two corporate subnets we wish to allow queries from
@@ -303,7 +301,6 @@ A second configuration in which selective forwarding occurs :ref:`is also
 provided<selective_forward_sample>`.
 
 .. code-block:: c
-        :linenos:
 
         // forwarding named.conf file
         // Two corporate subnets we wish to allow queries from
@@ -418,7 +415,6 @@ from the forwarded resolvers.  The configuration is closed, in that it defines
 those IPs from which it will accept recursive queries.
 
 .. code-block:: c
-        :linenos:
 
         // selective forwarding named.conf file
         // Two corporate subnets we wish to allow queries from