Document --no-conflicts-check for gnt-network

gnt-network add and connect do support the --no-conflicts-check option.
This is now also documented in the man pages.

This fixes issue 526.
Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

man/gnt-network.rst

@@ -41,6 +41,7 @@ ADD
 | [\--gateway6=*GATEWAY6*]
 | [\--mac-prefix=*MACPREFIX*]
 | [\--submit]
+| [\--no-conflicts-check]
 | {*network*}
 
 Creates a new network with the given name. The network will be unused
@@ -57,6 +58,9 @@ IPv6 semantics can be assigned to the network via the ``--network6`` and
 ``--gateway6`` options. IP pool is meaningless for IPV6 so those two
 values can be used for EUI64 generation from a NIC's MAC address.
 
+The ``--no-conflicts-check`` option can be used to skip the check for
+conflicting IP addresses.
+
 Note that a when connecting a network to a node group (see below) you
 can specify also the NIC mode and link that will be used by instances on
 that group to physically connect to this network. This allows the system
@@ -141,12 +145,17 @@ Displays information about a given network.
 CONNECT
 ~~~~~~~
 
-| **connect** {*network*} {*mode*} {*link*} [*groups*...]
+| **connect**
+| [\--no-conflicts-check]
+| {*network*} {*mode*} {*link*} [*groups*...]
 
 Connect a network to given node groups (all if not specified) with the
 network parameters *mode* and *link*. Every network interface will
 inherit those parameters if assigned in a network.
 
+The ``--no-conflicts-check`` option can be used to skip the check for
+conflicting IP addresses.
+
 DISCONNECT
 ~~~~~~~~~~