Corrects method name (#25568)

The method name was missing a 'd'. The method was not used anywhere
however, so no other code needs to be changed. Neither 'has_chilren'
nor 'has_children' are used in the codebase.

lib/ansible/module_utils/netcfg.py

@@ -81,7 +81,7 @@ class ConfigLine(object):
         return '\n'.join(config)
 
     @property
-    def has_chilren(self):
+    def has_children(self):
         return len(self._children) > 0
 
     @property