net: fix example IPv4 in dns docs

Author: Uzlopak

doc/api/dns.md

@@ -167,9 +167,9 @@ section if a custom port is used.
 
 ```js
 [
-  '4.4.4.4',
+  '8.8.8.8',
   '2001:4860:4860::8888',
-  '4.4.4.4:1053',
+  '8.8.8.8:1053',
   '[2001:4860:4860::8888]:1053',
 ]
 ```
@@ -820,9 +820,9 @@ addresses. If the port is the IANA default DNS port (53) it can be omitted.
 
 ```js
 dns.setServers([
-  '4.4.4.4',
+  '8.8.8.8',
   '[2001:4860:4860::8888]',
-  '4.4.4.4:1053',
+  '8.8.8.8:1053',
   '[2001:4860:4860::8888]:1053',
 ]);
 ```
@@ -937,9 +937,9 @@ section if a custom port is used.
 
 ```js
 [
-  '4.4.4.4',
+  '8.8.8.8',
   '2001:4860:4860::8888',
-  '4.4.4.4:1053',
+  '8.8.8.8:1053',
   '[2001:4860:4860::8888]:1053',
 ]
 ```
@@ -1389,9 +1389,9 @@ addresses. If the port is the IANA default DNS port (53) it can be omitted.
 
 ```js
 dnsPromises.setServers([
-  '4.4.4.4',
+  '8.8.8.8',
   '[2001:4860:4860::8888]',
-  '4.4.4.4:1053',
+  '8.8.8.8:1053',
   '[2001:4860:4860::8888]:1053',
 ]);
 ```