docs: networking: swap words in icmp_errors_use_inbound_ifaddr doc

Signed-off-by: NVincent Bernat <vincent@bernat.ch>
Link: https://lore.kernel.org/r/20210130190518.854806-1-vincent@bernat.chSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Documentation/networking/ip-sysctl.rst

@@ -1196,7 +1196,7 @@ icmp_errors_use_inbound_ifaddr - BOOLEAN
 
 	If non-zero, the message will be sent with the primary address of
 	the interface that received the packet that caused the icmp error.
-	This is the behaviour network many administrators will expect from
+	This is the behaviour many network administrators will expect from
 	a router. And it can make debugging complicated network layouts
 	much easier.