chore: improve formatting of namespace hint

Author: nikku

lib/write.js

@@ -500,12 +500,13 @@ ElementSerializer.prototype.parseGenericAttributes = function(element, attribute
     try {
       self.addAttribute(self.nsAttributeName(attr.name), attr.value);
     } catch (e) {
-      /* global console */
 
-      console.warn(
-        'missing namespace information for ',
-        attr.name, '=', attr.value, 'on', element,
-        e);
+      // eslint-disable-next-line no-undef
+      typeof console !== 'undefined' && console.warn(
+        `missing namespace information for <${
+          attr.name
+        }=${ attr.value }> on`, element, e
+      );
     }
   });
 };