Fix get_dns_facts on inexistent resolv.conf
diff --git a/lib/ansible/module_utils/facts.py b/lib/ansible/module_utils/facts.py
index bc611b41d0fa83..d7105b5a87ec8a 100644
--- a/lib/ansible/module_utils/facts.py
+++ b/lib/ansible/module_utils/facts.py
@@ -727,7 +727,7 @@ def get_env_facts(self):
 
     def get_dns_facts(self):
         self.facts['dns'] = {}
-        for line in get_file_lines('/etc/resolv.conf'):
+        for line in get_file_content('/etc/resolv.conf', '').splitlines():
             if line.startswith('#') or line.startswith(';') or line.strip() == '':
                 continue
             tokens = line.split()

This fixes the get_dns_facts function when /etc/resolv.conf is not present or unreadable.
