Misc wording fixes

lib/common/common_helper.rb

@@ -95,6 +95,7 @@ def last_update
   date
 end
 
+# Was it 5 days ago?
 def update_required?
   date = last_update
   day_seconds = 24 * 60 * 60

lib/wpscan/wpscan_helper.rb

@@ -49,7 +49,7 @@ def usage
   puts '-Use custom plugins directory ...'
   puts "ruby #{script_name} -u www.example.com --wp-plugins-dir wp-content/custom-plugins"
   puts
-  puts '-Update the DB ...'
+  puts '-Update the Database ...'
   puts "ruby #{script_name} --update"
   puts
   puts '-Debug output ...'