Retain the try do so an LDAP failure can fall back to local database.

This fixes tests but the automatic fallback may not be well documented behavior.

lib/pleroma/web/auth/ldap_authenticator.ex

@@ -65,6 +65,7 @@ defp ldap_user(name, password) do
 
     case :eldap.open([to_charlist(host)], options) do
       {:ok, connection} ->
+        try do
           cond do
             ssl ->
               :application.ensure_all_started(:ssl)
@@ -88,6 +89,9 @@ defp ldap_user(name, password) do
           end
 
           bind_user(connection, ldap, name, password)
+        after
+          :eldap.close(connection)
+        end
 
       {:error, error} ->
         Logger.error("Could not open LDAP connection: #{inspect(error)}")