Enable smtp extra property from Mail sending should be valid also for Invitation app

This improvement is related to Java Mail extra properties from Mail Sending and the Invitation smtp configuration.

At this moment, if you want to be functional the Invitation app, you must configure the e-mail server and also the invitation app. But, there is a detail that makes the difference in the user experience:

• If you set in Mail Sending - Javamail extra properties: mail.smtp.starttls.enable=true (taking into account that the others details from Mail Sending had been correctly configured) -> you will be able to share successfully a page by email.
• If you go Administration - Invitation app config, after you set all the correct values, you need to add again the value mail.smtp.starttls.enable=true (+ mail.smtp.localhost=my.server.hostname.com) to send successfully an invitation by e-mail.
• Without value mail.smtp.starttls.enable=true into Invitation app extra propr., the user will have an error displayed after filling the invitation form.

As an expected result, for a better user experience (and also avoiding errors in interface) I would prefer to :

• add only in Mail Sending - Javamail extra properties this value: mail.smtp.starttls.enable=true. This value should be called from Invitation app smtp - Javamail extra properties.
• set into Invitation app - Javamail extra properties only this value : mail.smtp.localhost=my.server.hostname.com
• This way, user won`t add twice the same value.