Remove if blank conditions from email unsetters

The User model methods that unset each of the secondary email values
if they are blank. In other words, if blank set to blank. That is
clearly unnecessary, so this removes the blank conditions to simplify.

app/models/user.rb

@@ -2007,19 +2007,19 @@ class User < ApplicationRecord
   end
 
   def set_notification_email
-    if notification_email.blank? || verified_emails.exclude?(notification_email)
+    if verified_emails.exclude?(notification_email)
       self.notification_email = nil
     end
   end
 
   def set_public_email
-    if public_email.blank? || verified_emails.exclude?(public_email)
+    if verified_emails.exclude?(public_email)
       self.public_email = ''
     end
   end
 
   def set_commit_email
-    if commit_email.blank? || verified_emails.exclude?(commit_email)
+    if verified_emails.exclude?(commit_email)
       self.commit_email = nil
     end
   end