Tidy up "diag_logs_vpn.php" XHTML

Move NOWRAP Boolean operator into CLASS statements
Add ALT and close IMG statements
Add SUMMARY to table statements
Deprecate ampersands
Close INPUT statements
Add closing BODY and closing HTML statements
Merge pull request #841 from ExolonDX/branch_16

Tidy up "diag_logs_vpn.php" XHTML