fix typos in html tags

This will satsify issue https://github.com/zammad/zammad/issues/2747 found by abeluck.

Earlier the two patched files did not correctly close divs, which caused broken Mails to be generated.

app/views/mailer/ticket_create/pl.html.erb

@@ -2,7 +2,7 @@ Nowe zgłoszenie (#{ticket.title})
 
 <div>Witaj #{recipient.firstname},</div>
 <br>
-<divOtrzymałeś nowe zgłoszenie (#{ticket.title}) od "<b>#{current_user.longname}</b>".</div>
+<div>Otrzymałeś nowe zgłoszenie (#{ticket.title}) od "<b>#{current_user.longname}</b>".</div>
 <br>
 <div>
 #{t('Group')}: #{ticket.group.name}<br>

app/views/mailer/ticket_escalation/pl.html.erb

@@ -15,4 +15,4 @@ Zgłoszenie (#{ticket.title}) zostało eskalowane
 <br>
 <div>
   <a href="#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}" target="zammad_app">#{t('Zobacz w Zammad')}</a>
-</div
+</div>